FORENSIC BALLISTIC
BALLISTICS – is the science of the motion of projectile.
ORIGIN OF BALLI STIC – The word “BALLISTICS” or iginat ed f rom the
Greek wor d “Ballein” which means “to throw” and f rom the Roman
word “Ballista” which is machine to hurl a stone.
-From those words t he modern term f or Forensic Ballist ics was
derived to indicate t he science of moving projectile.
BRANCHES OF BALLISTICS
a. )
INTERIOR BALLI STICS – traits of the motion of the projectiles
while still in the f irearm, namely t he studies o f combustion of the
powder, pressur e developed and velocit y.
b. )
EXTERIOR BALLI STICS – traits of the motion of the projectiles
af ter leaving the muzzle namely traject ory, velocit y, range penetration,
etc.
c. )
TERMINAL BALLISTICS – traits of the eff ects of the projectile
on impact on the tar get.
d. )
FORENSIC BALLIST IC – the science of f irearms ident if ication
by means of the ammunit ion f ired throug h them.
DIVISION OF FORENSIC BALLISTICS:
a. )
FIELD NVESTIGATION – ref ers to the work of an invest igation
in the f ield. It concerns most ly with the collect ion, marking,
preser vat ion, packing and transmission of f irearms evidences. It
include the study of class charact erist ics of f irearms and bullets.
b. )
TECHNI CAL EXAMI NATION – ref ers to the exam iners who
examine bullets/ or shells, whether f ired f rom also whether or not
cartridges wer e loaded and ejected made by the suspected f irearms
submitted. Reports are made by the exam iners and test ify in court
regarding their repor ts.
LEGAL DEFINITION OF FIREARM – “Firearms” or “Arms” are herein
used includes r if les, muskets, carbines, shotguns, revolver s, pistols
and all other deadly weapons f rom which a bullet, ball, shot, shell or
other missile may discharge of f by means of gunpowder or other
explosives. The ter m a lso includes air rif les except such as being of
small caliber and lim ited range used as toys. The barrel of any f irearm
shall be considered a complete f irearm for all purposes her eof (Sec.
877, Revised Administrative Code see also Sec. 290 National Interna l
Revenue Code).
TECHNI CAL DEFINI TION OF FIREARM – instrument used f or the
propulsion of a pr ojectile by means of expansive f orce of gases f rom
burning powder.
AMMUNITION (def ined) – under the Nat ional Inter nal Revenue Code
the word “Ammunit ion” shall me an loaded shell f or rif les, muskets,
carbines, shotguns, revolvers and pist ols from which bullets, ball shot,
shell or other missile may be ammunit ion f or air rif les.
PRINCIPLES OF IDENTIFICATION (BULLETS)
1.
No t wo barrels ar e microscopically ident ical as the surf ace of
their bores all possesses individual characterist ics markings
of their own.
2.
W hen a bullet is f ired f rom rif led barrel, it becomes engraved
by the rif ling and this engraving will var y in its m inute details
with ever y individual bore. So it h appens that the engraving
on the bullets f ired f rom one barrel will be diff erent f rom
another bullet f ired f rom another barrel.
3.
Ever y barrel leaves its thumb mark or f ingerprint on ver y
single bullet f ired t hrough it just as ever y breech f ace leaves
its thumb mark on the base of ever y f ired cartridges case.
PRINCIPLES OF IDENTIFICATION (SHELLS)
1.
The breech f ace and striker of ever y single f irearm leave
microscopical individualit ies of their own.
2.
The f irearm leaves its “f ingerprints” or “t humb mark” on ev er
cartridges case which it f ires.
3.
The whole pr inciples of identif ication is based on the f act
that since the breech f ace of ever y weapon must be
individually dist inct, the cartridges cases which it f ires ar e
imprinted with this individualit y. The imprint s on all
cartridges cases f ired f rom the same weapon are always the
same; those on cartridges cases f ired f rom diff erent weapons
are dif f erent.
TYPES OF PROBLEMS: There
Forensic ballistic, namely:
are
six
(6)
types
of
problem s
in
Type 1Given bullets, t o det ermine the caliber and t ype of f irearm
f rom which it was f ired.
Type 2Given a f ired cartridge case, to determine the caliber and
type of f irearm from which it was f ired.
Type 3Given a bullet and a suspected f irearm, to determine
whether or not t he bullet was f ired f rom the suspected f irearm .
Type 4Given a f ired cartr idge case and a suspected f irearms, to
determine whether or not t he cartridg e case was f ired f rom the
suspect ed f irearm.
Type 5Given t wo or more bullets, to det ermine whether or not
they were f ired f rom only one f irearm.
Type 6Given t wo or mor e cartridges cases, to determine whether
or not they were f ired f rom only one f irearm.
CLASS CHARACTERISTICS – Those which are determine prior to the
manuf acturer of the firearm and are within control of man. These ser ve
as basis to ident if y a certain class or group of f irearm.
a
b
c
d
)
)
)
)
Caliber (Bore Diameter)
Number of lands
Number of grooves
W idth of lands
e ) W idth of grooves
f ) Direction of twist
g ) Pitch of rif ling
h ) Depth of grooves
INDIVI DUAL CHARACTERISTICS – Those which ar e determinable only
af ter the manuf acture of the f irearm. They are character istics whose
existence is beyond the control of man and which have random
distr ibut ion. Their ex istence in a f irearm is brought about by the tools
in their normal operation r esulting through wear and t ear, abuse,
militilat ions, corrosion, erosion and other f ortuitous causes.
SMALL ARMS – f irearms which propel pr ojectiles of less than one inch
in diameter.
TYPES OF SMALL ARMS GENERAL:
a )
Smooth-bor e – f irearm which do not have rif ling
Ex: shotguns, muskets
b )
Rif led- bore – f irearm which cont ain rif ling marks.
Ex: pistols, revolvers, rif les
SMALL ARMS AMMUNITION – small arms ammunition co nsists of
cartridges used in r if les, carbines, revolvers, pist ols, sub -machineguns
and shell used in shotgun.
EQUIVALENT OF CALIBERS IN INCHES AND MILLI METERS:
a ) Caliber .22
b ) Caliber
c ) Caliber .32
d ) Caliber .30
e ) Caliber .38
f ) Caliber .45
g ) Caliber .30
– About
.25 –
– About
– About
– About
– About
– About
5.59 mm.
About 6.35 mm.
7.65 mm.
7.63 mm. (mouser)
9
mm.
11
mm.
7.56 mm. (Luger)
RIFLING – consist of a number of helical grooves cut in the inter ior
surf ace of the bore. The rif ling in f irearms may be divided into t he
f ollowing types:
a )
Small t ype – f our grooves, right hand t wist, grooves and lands
of equal width. (4R G -L)
b )
Smith and W esson type – f ive grooves, r ight hand t wist, grooves
and lands of eq ual width (5R G -L)
c )
Browning type – six grooves, right hand twist, narrow lands and
broader grooves (6R G2X)
d )
Colt t ype – six grooves, lef t hand twist, narrow lands and
broader grooves (6L G2X)
e )
W ebley t ype – seven grooves, r ight hand twist, narrow lands and
broader grooves (7R G3X)
f )
Army t ype – f our grooves, r ight hand t wist, narrow lands and
broader grooves (4R G3X)
PURPOSE OF RIFLING – is to impact a motion of rotation to a bullet
during its passage inside the barrel in order to insur e gyr oscopic in
the f light, and so that it will travel nose - on towards the target.
PARTS OF CARTRI DGES
a)
Bullet
b ) Shell
c )
Gunpowder
d ) Primer
TYPES OF CARTRI DGES:
a )
Pin-f ire – the pin ext ends radically t hrough the need of the
cartridges case int o the primer.
b )
Rim-f ire – the pr iming mixture is placed in the cavit y f ormed in
the rim of the head of the cartridges case. The f lame produced is in
direct communicat ion with the powder charge. Used in the calibers
.22, .25 and .45 Derr inge r pistols.
c )
Center-f ire – the primer sup is f orced into the middle port ion of
the head of the cartridges case and the priming mixture is exploded by
the impact of the f iring pin. The f lame is communicated to the powder
charge through the vents leading into the powder charge.
TYPES OF CENTER- FIRE CARTRIDGES:
a )
Rimmed t ype – the r im of the cartridges case is greater than t he
diameter of the body of the cartridges case. Ex: Cal .38 and Cal .22
b )
Semi r immed t ype – the rim of the cartridge case is slig htly
greater than the diameter of the body of the cartridges case. Ex: Cal.
Super .38 auto, Pist ol, .32 and .25
c ) Rimmed less t ype – the r im of the cartridges case is equal t o the
diameter of the body of the cartridge case. Ex: Cal .45 Auto Pistol . 30
carbine .223
PROCEDURE AT THE SCENE OF SHOO TING CASES
W hen an off icer arr ives upon the scene of a shoot ing case, he is
usually conf ronted by a condit ion of utter conf usion. Neighbors
and onlookers are crowded ar ound the place; relatives are
weeping and hyster ical. I n his career as an off icer he will m eet
with other situat ions which require as m uch as much poises tact
and common sense when he appears upon the scene of
homicide.
His f irst dut y is to clear the pr emises of all persons so that an
intellig ent invest igation is not a matter of f ive or ten minut es,
but it requires that a def inite r outine shall be f ollowed, if
mistakes are to be avoided. Things should be done, which may
appear wholly unnecessar y at the t ime, but only to become
vitally important later. One can never f orces the angels t hat will
develop and it is f ar better to do a hundr ed things unnecessarily
than to m iss doing one that m ight mean the solut ion of the case.
The victim is dead and will stay dead. The off icer may be
important by repo rters or other to do things which he is not yet
ready to do – t o give statement to the press or to dr aw
conclusion. In spite of all persuasions, he should bear in m ind
that there is one purpose and one purpose only, and that is to
carry out an intelligent investigation.
Upon r eceiving a cell to the sense of a shoot ing case, t he off icer
should always take along with him a loose -leaf notebook and
f ountain pen to make notes at the time and on the place and not
trust to his memory to reconstruct the situat ion at his
convenience.
W hen the off icer is
should f ollow a
wr it ing at the
ref erences and
are as f ollows:
summoned on such an err and, his procedure
logical patter n. His observat ion should be put in
time of his investigat ion to keep f or f uture
to produce in court if necessar y . These steps
1. Note accurately in wr it ing the time he received the call and by
whom it was sent.
2. Note accurately the time he arrive at t he scene and the corr ect
address.
These f irst two it ems seem to be trivial, but it is amazing how
of ten in court they become of vital importance. It is not
uncommon that the off icer is unable to f ix the t ime accurately
within an hour to the satisf action of a jury.
3. He should ascertain if the victim is dead, and if not non -medical
aid or remove the body to a hospital, ot her wise the body should
not be disturbed.
4. Immediately clear the premises of all bystanders and under no
circumstances allow anyone to touch or remove anything in the
vicinit y.
5. Use ever y eff ort and means to ident if y the deceased.
6. Does the body lie where the shoot ing took place? Of ten, before
the of f icer arrives the body will be moved by a bystander.
Frequently it will be picked up of f the floor and put a bed or
taken from one room to another.
7. Take the names and addresses of all wit nesses an d take writ ten
notes on the statement of as many persons as practicable.
8. Photograph the body f rom all angels to show its relat ionship to
doors, windows, f urniture’s and other objects in the room.
9. Measure with a tape the exact distance of the body wit h re lation
to the previously mentioned f ixtures of the premises.
10.
Note in wr it ing the exact posit ion wher e he f ound the body
whether he f ound it lying on the side, back or abdomen t hat
objects if any, were in the hands; reports what was the
conditions of the c lot hing and the amount of bleeding.
11.
Examine the ceiling, f loor and f urnit ure f or bullet holes,
blood stains, f ired bullets, f ired shell or shotgun wadding.
12.
If there is a f irear m at the scene, he should mote in
wr it ing the f ollowing obser vat ions:
a. Exact ly where f ound.
b. Type of weapon – automatic pistol, revolvers, rif le, or shot
gun, caliber or gauge designation.
c. Make and ser ial numbers and at that t ime he should mark
his init ials on the butt or f rame of the weapon f or f uture
identif icat ion.
d. Other distinct f eatures.
13.
At the crime scene note down wher e t he empt y shells,
bullets and/ or f irearms where f ound and make a diagram to
illustrates the same, to show their relat ives dist ances f rom the
body of the vict ims, Photograph if possible.
14.
Be caref ul in handling a f irearm f ound at the scene of the
crime f or they may have latent f ingerprint on the parts of the
f irearm. Note down the t ype, kind, m ake caliber and serial
number. If there are f ingerprints, submit said f irearm to a
f ingerprint technician but be sur e th at the f irearm should not be
disturbed.
15.
Mark the empty cartridges cases inside or near the mouth
by scr atching the initials to the investigat ion or the initials of the
vict ims.
16.
Mark the bullets at the give (or nose) by scr atching the
investigation’s init i als of the vict im but def initely NOT at the
rif ling marks (landmarks and groove mar ks).
17.
Mark the empt y shotgun shells wit h indelible ink at the
body.
18.
The barrel of the f irearms must be marked too.
19.
Af ter marking the empty shells and bullets, wrap them
separately and individually wit h sof t tissue paper and note down
on the wrapper where each was f ound t he time and dat e. The
purpose of wrapping them separately is to avoid being
scratched.
20.
W hen a lead bullet is f ound at the scene of the crime the
body of the vict im, the presumpt ion is that a Revolver was used.
21.
W hen a jacketed bullets is f ound at the scene of the cr ime
or in the body of the vict im, it can be measured that a presumed
that a Automat ic Pist ol or Automatic W eapon was used.
22.
W hen an empt y shell i s f ound at the scene of the crime,
the presumpt ion is an Automat ic Pistol or W eapon was used.
23.
W hen one empty shell is f ound at the scene of the crime,
the presumpt ion is a Revolver was used.
24.
In the bore of a barrel, the depressed portions are the
grooves, and the raised are the lands.
25.
On a f ired bullet, it is the reverse. The landmarks are the
depressed portions, and the groove marks are the raised
portions.
26.
To determine the r eal direction of the rif ling twist in a
rif led barrel, peep t hru the barrel, p lace a land or groove in
inclines to the right, then it has a right t wist and if it inclines to
the lef t, then the rif ling twist is lef t.
27.
To determine the dir ection of the twist of a bullet, look on
the bullets in an elongated position. If the landmarks a nd groove
marks incline to t he right, then it has a right t wist and if it is
inclines t o the lef t, then the r if ling twist is right. If the inclinat ion
is lef t then it is a lef t twist.
28.
A f ired bullet will acquire the class char acterist ics of the
bore of the barrel f rom which it was f ired. So t heref ore if a bore
has class characteristics of .45 caliber, .6 lands, .6 grooves,
right t wist, groove wider than the land, each character ist ics will
be marked on the bullet it f ires.
29.
It is the rif ling of the bore tha t marked a fired bullet.
30.
So if a f atal will have the same class character ist ics as
the bore of the suspected gun, then it is possible that the bullets
could have been f ired f rom the suspected gun.
31.
To determine def init ely if the bullet above was f ired or not
f rom a suspected gun, then the case must be sent to a Forensic
Ballist ics Experts who will conduct the pr oper exam inat ions.
32.
If two bullets do not have the same class character istics,
def initely and conclusively they wer e NOT f ired f rom the same
barrels.
33.
If a f atal bullets does not have the same class
character ist ics as the suspected f irearm (barrel), then
conclusively the bullets was not f ired f rom said barrel.
The f ollowing are suggestions f or the investigator to obser ve in
testif ying in courts of j ustice:
1. Be prepared.
2. Be calm and well poised.
3. Tell the truth, not hing but the truth.
4. Be courteous.
5. Be natur al and sit straight f orward.
6. Do not volunteer.
7. Keep your temper.
8. Listen to the question asked bef ore giving your answer.
9. Speak loud enough to be hea rd.
10.
W atch your personal appearance and conduct in the
courtroom.
11.
Answer only what you are asked, no mor e.
DEFI NITIONS OF TERMS
1.
PERCUSSION – Action when the pr iming mixture of chemical
compound hit or struck by f iring in would ignite.
2.
JUXTAPOSITION – Two objects is evidence bullet and test
bullet are examined and compared under the bullet comparison
microscope. Includes also the exam inat ion of f ired shells.
3.
BALLO or BALLEI N – Greek wor ds wher e Ballistics was der ived
f rom which means “t o throw”.
4.
BALLISTA – The ear ly Roman was Machine – a gigant ic bow or
Catapult.
5.
BALLISTICS – Science of the motion of projectiles.
6.
FORUM – A Greek word of f orensic which means debat able,
argumentation in relation to the court of justice.
7.
FORENSIC BALLIASTICS - The study of f irearms identif icat ion
by means of ammunition f ired f rom them.
8.
BALLISTICIAN – Person whose knowledge in ident if ication is
accepted by the cour ts and other investigation agencies.
9.
ABRASSION – (in the
cleaning materials, or
abrasive mat erial was
and wear ing away of
bullets.
10.
BLACK POW DER – A mechanical m ixtur e of charcoal, sulf ur and
salt paper. Bur ned with considerable whit e smoke.
11.
CARTRIDGE – is a complete unf ired unit of bullets, cartridge
case, gunpowder and primer.
12.
AMMUNITION (legal) – SEC. 877 of the RAC – shall mean
“loaded shell” f or rifles, muskets, carbines, shotguns, revolvers
and pist ols which a ball, bullet shot shell or other m issile maybe
discharges by means of gunpowder or ot her explosive. The term
includes ammunition f or a rif les as mentioned else where in the
code.
world) Scratches cause by using improper
by f iring ammunition with bullets to which
adhering. Normal enlargement of the bore
lands due to the abrasive act ion of the
Ammunit ion (technical) – ref ers to a group of cartridge or to a single
unit cartridge, meaning a complete unf ired unit consist ing of bullets,
cartridge case, gun powder and primer. The term may also ref er to a
single round.
13.
BALL BU LLETS – Bullets have sof t lead course inside a jacket .
14.
ROUND – one single complete cartridge.
15.
BULLET ENERGY – the powder possessed by a moving bullet,
or in ot her words its abilit y to keep going meets an obstacle of
immense importance, f or obviously, the more powder a bullet
has and t he harder it is to stop the, more eff ective it can be as a
weapon.
16.
BULLET RECOVERY BOX – consist of a wooden box, 12” x 12”
x 96”, with the hinged to cover and with one end open. This long
box is f illed with or dinar y cotton and separated int o section by
card boar d partit ions.
17.
CALI BER – is the diameter of the inner surf ace of the barrel that
is measured f rom land to land.
18.
DUMDUM BULLET – “Dumdum” is an out molded and gener ally
misused term. It was an unoff icial name f irst ap plied hallow
point bullets maid at the Brit ish arsenal at Dumdum, India.
19.
EROSION – the mechanical wear and tear of the inner surf ace
of the gun barrel due to the mechanical abrasion or gliding.
20.
CORROSION – the mechanical wear and tear of the inside of
the gun barrel due to rust f ormation or chemical act ion of the by
products of combust ion af ter f iring.
21.
CANNELURE (bullet ) – A knurled ring or serrated grooved
around the body of the bullet which cont ains wax f or lubr icat ion
in or der to m inimize f riction d uring the passage of the bullet
inside the bore.
22.
CALI PER – an instrument used f or making measurement such as
bullet diameter and bore diameter.
23.
CHILLED SHOT – shotgun pellets made f rom lead especiall y
hardened by the addition of a slight amount of antimo ny.
24.
CLASS CHARACTERISTICS – are those that are determinable
even bef ore the manuf acture of the f irearm. It is categorized
into caliber or gauge number of lands and grooves, width of land
and grooves, t wist of rif ling, patch of rif ling and dept h of
grooves.
25.
RANGE – the straight distance bet ween muzzle and target.
26.
POINT BLANK RANGE – popularit y used to indicate t he dist ance
the bullet will travel bef ore it drops enough to require sight
adjustment. A shot f ired so closed t o the target that no sighting
is necessar y f or eff ective aiming.
27.
MAXI MUM RANGE – the f arthest distance that a projectile can
be propelled f orm a firearm.
28.
GALLERY RANG E – the indoor targets range on properly
constructed indoor r anges, f iring maybe conducted wit h center
f ire pistols and rev olvers at range of 25 years and 50 years.
Such installat ion are generally r ef erred to as indoor ranges the
term galler y being applied usually only t o short range 22 caliber
installat ion.
29.
EXTREME RANGE – the greatest distance the bullet will travel
the cartridge is f ire.
30.
EFFECTIVE RANGE – the maximum distance at which a bullet
may reasonable be expected t ypes of live target.
31.
ACCURATE RANG E – the distance with in which he shoots has
control of his shots.
32.
FOULING - the accumulat ion of a deposit wit in the bore of a
f irearm caused by solid by products r emaining a cartridge is
f ired.
33.
GUM COTTON – a ver y powerf ul explosive, like nitroglycer ine
which is a chemical compound and not a mixture. This is f ormed
by the action of nitr ic and sulf uric acid on cotton or nay ot her
kind of cellulose.
34.
LANDS – t he raised portion bet ween the grooves in the int erior
surf ace of the gun barrel.
35.
LAPPING – is the smoothening of the inner surf ace of the
barrel.
36.
MACHI NE REST – a machine used f or testing the accuracy of a
f irearm.
37.
KNOCKING POW ER – power of the bullet which believer of a
ver y paralyzing blow that put the victim down and may t hen
recover if the wound inf licted upon is not f atal.
38.
STOPPING POW ER – power of the bullet which put the victim
out of the action instantly. So it should be understood that
stopping power is not necessarily the same thing as killing
power. However, st opping power depends ver y largely on the
location of the shot.
39.
PRI MER – the complete assembly of cup, priming composit ion,
paper discs and anvil.
40.
CARTOUCHE
OF PAPER.
41.
CHARTA – Lat in wor d f or cartridges which means PAPER.
– French word of cartridge which means RO OL
ORIGIN OF FIREARM
13 t h Centur y – development of f irearms f ollowed the invention of
gunpowder in W estern Europe.
Berthold Schwart z – a German monk, and Roger Bacon, an English
monk are both credited with gunpowder invent ion.
- Most ref erence books credit Roger Bacon, English monk and
Scientist with the invention of gunpowder in 1248 and Bert hold
Schwart z, with application of gunpowde r to the propelling of a
missile in the early 1300’s. This powder was that we now call
“Black Powder”.
1245 – Gen Bat u, The Tartar leader, used artiller y in Liegnits when he
def eated the poles Hungarians, and Russians.
- It is also of ten stated that the gunpowder was f irst invented by
Chinese, wer e of gunpowder and its use as pr opellant long
bef ore its advantages became recognized in Europe.
- It may also assum e the Arabs wit h their advance knowledg e of
chemistr y at that t ime.
1247 – One of the earliest recorded uses of f irearms in war f ar was
that of an attack on Seville, Spain.
1346 – Cannons used by King Edward II of England at Crecy.
1335
-
Mohammad II of turkey in his f amous conquest of
Constantinople.
-First f irearms were inef f icient, large and h eavy and were not
capable of being carried by an individual soldier; hence, the
development of cannons preceded that of small arm weapons by
almost 50 years.
Man never sat isf ies to himself . He is always trying to improve himself
and his surrounding . He cr eated some rule crude or pr imit ive
weapons which were subsequently developed into sophist icated
f irearms of modern times.
The f ollowing are the stages of development of man’s weapon:
1.
2.
3.
4.
5.
6.
7.
Stones
Cubs Knives Spears and Darts
Sling shots to hur l objects
Bows and arrows
Cross – bows
Guns
Missiles
1.
Col. Calvin H. Goddard M.D, OS Army – Father of Modern
Ballist ics.
2.
Horace Smith – Founded the great f irm Smith and W eapon and
pioneered the making of breech – loading regales.
3.
Daniel B. W esson – An associate or partn er of smith in revel
ver b making.
4.
John M. Browning – W izard of modern f irearms and pander ed
breech loading single shot rif le.
5.
John T. Thompson – pioneer ed the making of Thompson sub Machine.
6.
David “Carbine” W illiams – maker of f irst know carbine.
7.
Alexander John Forsythe – Father of the percussion system.
8.
Elisha King Root – Designed machiner y of making colt f irearms.
9.
Eliphalet Rem ington – One of the f irst rif le makers.
10.
John Malon Martin – Founder of martin Firearms Company.
11.
James W olf e Ripley – Stimulated the development of the model
1855 r iff led – musket.
12.
Samuel Colt
revolver.
13.
Henr y Derr inger – He gave his name to a whole classes of
f irearms.
14.
John C. Garand – Designed the sem i -automatic US Rif le, Cal.
30
15.
Oliver F. W ichester – One of the earliest rif les and pistol
makers.
– (1814-1862)
– Produced the f irst pract ical
I MPORTANT DATES IN FIREARMS HISTORY
1313 ---Gunpowder as a propellant. Te age of gunpowder began with
outs f irst use as a propellant f or a pr ojective. Such use has been
recorded as ear ly as 1313.
1350 ---Small arms, Gunpowder was f irst used only in cannons. It was
in the m iddle of the 14 t h centur y t hat portable hand, F.A was
introduced. These guns were ignited by a hand -held wire or lighted
match.
1498 --- Rif f ling, The f irst ref eren ce to rif led barrels appeared.
Although its important as an aid to accur acy was recognized by some,
it was many years af ter bef ore rif ling was generally used.
1575 ---Cartridges, Paper cartridges combining both powder and ball
were developed. This greatly speeded loading and reduced the
hazards of carrying loose powder.
1807 ---Percussion system, the discover y of Forsythe in 1807 the that
certain compounds detonat ed by a blow would be used to ignit e the
charge in a f irear m, f or the basis f or all later per cussion and
cartridges developm ent.
1835 ---Samuel Colt -patented the f irst pr actical revolvers in which the
cylinder was rot ated by cooking the ham mer.
1836 ---Pin f ire. Cartridge. Developed by Le Faucheux in 1836, was
probably the f irst self really the f irst rim fire cartridge.
1858 ---Center f ire Cartridge. The Morse Cartridge of 1858 m arked the
beginning of the rapid development of the center f ire cartridge.
1884 ---Automatic Machine Gun. Hiran Maxim built the f irst f ully
Automatic gun, utilizing the recoil of the piece to load and f ire the next
charge.
1885 ---Smokeless Powder. In Fr nece, Veille, Developed the f irst
satisf actor y smokeless powder, a new pr opellant which not only lacked
the smoke character istics of black powder, but also more powerf ul .
1845 ---Rimf ire Cartridge. In France, Florbert develop a “bullet”
“breech cap” which was in really the f irst rimterf ire Cartridge.
I.
II.
TW O GENERAL CLASSES OF FIREARM (ACCO RDING TO Gun
Barrel Internal Const ruction)
A.
Smooth-bor e f irearms – f ire arms the have no rif ling (land and
grooves) inside their gun barrel.
Ex. Shot guns and muskets
B.
Rif led-the bore Firearms – Firearms that have r if ling inside
their gun barrel.
Ex. Pistols, Revolver s, Rif les
MAI N TYPES OF .As. (Accor ding to Caliber of Projectiles
Propelled)
A. Artiller y – Those t ypes of f irearm that propel pr ojectiles more
than one inch in diameter.
Ex. Cannons, Mortar s, Bazookas
B. Small Arms – Propel Project iles less than 1 inch in diam eter,
Can be oper ated by one man.
Ex. Machines guns Shoulder arm and ha nd arms
III.
TYPES OF FI REARMS According to Mechanical Construct ion
A. Sing le Shot F.A – t ype of f irearms designed to f ire only one shot
f or ever y loading.
Ex. Pistols, Rif les, Shot guns – sing le shots
B. Repeating Arms – Fire several shots in one loading
Ex. Rif les, Shot guns
C. Bolt Act ion T ype – Reloading is done by manipulat ion of the
bolt.
Ex. Rif les, Shot guns, Machine guns
D. Automatic Loading Type –Af ter the f irst shot is f ired, autom atic
loading or f eeding of the chamber takes place.
Ex. Rif les, Shot guns
E. Slide Act ion Type (Trombone) –Loading takes place by back and
f orth manipulation of the under f orearm of the gun.
Ex. Rif les, Shot guns
F. Lever Type (Break Type) –Loading takes place by lever action of
the Firearm.
Ex. Rif les, Shot guns
IV.TYPES OF FI REARMS accor ding to USE
A. Militar y Firearms
Ex.
1. Pistols
2. Revolvers
3. Rif les
4. Machine Guns
B. Pocket and Home Def ense F.A
Ex.
1. Pistols
3. Rif les
2. Revolvers
IV.
UNUSUAL OR MISCELLENEOUS TYPE
--Those t ypes of f ire arm that is unique in mechanism and
construct ion
1.
2.
3.
4.
Palt ik Pistols
Palt ik Revolvers
Palt ikRif les
Palt ik Shot Guns
THE THREE MAIN PARTS
REVOLVERS – Cal . 38
PISTOL –Cal .45
1. Barrel assembly
2. Cylinder Assembly
3. Frame or Receiver
1. Barrel Assembly
2. Slide Assembly
3. Frame or Receiver
RIFLE – Cal .30
12
SHOT GUN – Gaug e
1. Barrel Assembly
2. Magazine Assembly
Assembly
3. Stock Group
1. Barrel Assembly
2.
Magazine
3. Stock Group
DETAILED PARTS
REVOLVER .38
1. Barrel Assembly
a. Breech end
b. Muzzle end
c. Bore
d. Rif ling (lands and grooves)
AUTO MATIC PISTOL .45
1. Barrel Assembly
a. Breech end
b. Muzzle end
c. Bore
d. Rif ling (land grooves)
e. Chamber
f . Interlocking ribs
g. Barrel lug
h. Barrel link
i. Barrel link pin
j. Barrel lead (lead)
2. Cylinder Assembly
a. Chambers
b. Extractor
c. Extractor rod
d. Racket
e. Cylinder groove
f . Yoke
g. Cylinder locking Notches
3. Frame or Receiver
a. Top strap
b. Rear sight
c. Breech Face
d. Hammer
e. Spur
f . Thumb latch
g. Side plate
h. Back
i. Firing pin
j. Butt
k. Front strap
l. Trigger guard
m. Trigger
n. Cylinder lock
o. Right side stock
p. Lef t side stock
q. Trade mark (monogram)
r. Serial number
2. Slide Assembly
a. Front sight
b. Top strap
c. Ejection port
d. Rear sight
e. Breech block
f . Breech Face
g. Extractor
h. Firing pin
i. Fir ing pin top
j. Serrations
k. Trade mark
l. Model
m. Interlocking lu gs
3. Frame or Receiver
a. Ejector
b. Hammer
c. Spur
d. Grip saf ety
e. Thumb saf ety
f . Disconnector
g. Back strap
h. Butt
i. Lanyard loop
j. Front strap
k. Magazine well
l. Right side sto ck
m. Lef t side stock
n. Trigger
o. Trigger guard
p. Model
q. Plunger
r. Serial num ber
The automatic Pistol -Caliber .45 besides having the main parts
and detailed it has also the so called auxiliar y parts ( accessor ies)
which must all be removed bef ore disassembly of the weapon can be
accomplished.
1. Recoil Plug
2. Barrel Bushing
3. Slide st op pin
4. Recoil Spr ing
5. Recoil Spr ing
ADVANTAGE OF REVOLVER
1.
It is an old standard weapon, ever y one is used to it, and alm ost
ever y one knows something about to handle it.
2.
The revolver is saf er f or inexper ienced people t o handle and
carry then an autom atic pistol.
3.
The mechanism of a revolver allows the trigger pull to be bet ter
then that of the average automatic weapon.
4.
A misf ire does not put revolvers out of action.
5.
It will handle satisfactorily old or new or partly deteriorated
ammunit ion which g ives a reduced velocit y that would jam an
average automat ic pistols.
DISADVANTAGES OF A REVOLVER
1.
It is more bulk y to carry than that of an automatic pist ol.
2.
Its grip on handle is generally not as good as that of pistol.
3.
It is hard to cle an af ter f iring.
4.
It is slower to load.
5.
It is harder to replace worn out or broken parts, it is f actory job.
6.
W orn out or poorly made weapon is subject to var iable accuracy
due to impr oper up of cylinder.
ADVANTAGES OF AN AUTO MATIC PISTOL
1.
It as a better grip f its the hand points naturally.
2.
It is more compact for the same f ire power.
3.
It is easier to load than a revolver.
4.
In case of worn or corroded barrel a new one can be put in at
litt le expense without sending the gun to the f actory.
5.
It gives a grea ter number of shots than revolvers.
6.
It is easier to clean t han revolvers.
7.
It gives greater f ire power and greater ease of f iring.
8.
There is no gas leakage in its operat ion.
DISADVANTAGES OF AN AUTO MATIC PISTOL
1.
Ammunit ion must be pref ect. Old and deteri or ated ammunition
will cause a jam.
2.
A misf ire stops the f unctioning of the gun.
3.
W hen the gun is kept loaded f or a long period of time, the
magazine spr ing is under tension and may det erior ate and
cause trouble.
4.
The automatic pistol can not use blank or reduced loads.
5.
It has a poor trigger pull than the revolver.
6.
The magazines r equire a jacketed bullet which is not as good f or
practical use as that of lead bullet.
7.
The automatic pist ol is more dangerous to handle and f ire
especially f or inexperienced pe ople due to the f act that af ter
one shot it is always cooked and loaded.
8.
It is not adapted to reloading. It throws away empt y shell at
each shot.
9.
Its mechanical act ion ejects empt y shell towards the f ace at
each shot.
10.
Its throws
evidence.
out
empty shells on the
ground to remain
11.
It can not be f ired f rom the pocket without jamming.
as
EVERY POLICE OFFICER should f requently check his revolvers f or:
1.
Obstruction in the barrel.
2.
Bulg ing or swollen barrel.
3.
Fir ing pin protrusion through recoil plate when tr igger is in
rear ward position.
4.
On older revolvers, the impr int of the pr imer on t he recoil plate
in relation to the f iring pin hole (to insur e blow in center of the
primer).
5.
Evidence of “spitting lead” around breech
complaints of f ellow sho oters in the f iring line.
6.
Tightness of all side plate screws.
7.
Tightness of ejector if the weapon is a Smith and W esson
revolvers.
8.
Cleanliness and pr ojective f ilm of oil to prevent rust.
of
barrel
f or
NO MENCLATURE AND FUNCTION
BARREL – init iates the path of the bull et.
FRAME – Houses the internal parts.
YOKE – Connecting pivot bet ween the f rame and cylinder.
EXTRACTOR – Pulls the empt y shells f rom the cylinder
simultaneously.
EXTRACTOR ROAD – Activates the extr actor and is a locking device.
CENTER PI N – Ser ves as a looking device f or the cylinder.
CENTER PI N SRPING – Holes the cent er pin in a locked posit ion.
SIDE PLATES – Provides access to the internal parts.
SIDE PLATE SCREW – Hold the side plate and yoke in place.
HAMMER BLOCK – Saf ety device that prevents hammer blow t o
primer.
DOUBLE ACTION SEAR – Built into the weapon to allow double action
f ire.
HAMMER – Strikes the blow that initiates or ignites pr imer.
BOLT – Disengage center pr im to allow opening of cylinder and blocks
hammer.
THUMBLATCH – Act uates bolt to release the cylinder.
HAND (pawl) – Rotat es the cylinder when the hammer is cock ed.
CYLI NDER STOP – Stops and holds the cylinder alignment f or f iring.
TRIGGER – Actuates the parts necessar y to f ire the weapon.
TRIGGER GUARD – Guards the tr ig ger f rom unnecessar y action to
avoid accidental f iring.
REBO UND SLIDE – Returns trigger, actuates hammer block and locks
hammer.
TRIGGER SPRI NG – Provides energ y f or return movement or rebound
slide.
TRIGGER LEVEL – Contacts rebound slide to return trig ger for ward.
MAI N SPRING – Pr ovides energy to the hammer to activate f iring
mechanism.
STRAIN SCREW – Controls tension of the mainspring.
TRIGGER STOP – Prevents excessive rear ward movem ent af ter
hammer the release.
RACKET – Helps in t he withdr awal of the Cartridges or shells f rom the
chambers of the cylinder.
CYLI NDER NOTCH – It helps hold the cylinder in place and aligned
ready f or f iring.
NO MENCLATURE O F CARTRIDGE
1.
Bullet – A projectile propelled f rom a f irearm by means of
explosive f orce of gases coming from burning powder.
2.
Cartridge Case – A tubular metallic cont ainer f or the gunpowder
sometimes called shell.
3.
Gun Powder – Is the propellant which when ignited by the primer
f lash is converted to gas under high pr essure and propels the
bullet or sh ot charge through the barrel and on the target.
4.
Primer – The metal cap containing the highly sensit ive priming
mixture of chemical compound which when hit or struck by the
f iring pin would ignite, such act ion is called “PERCUSSION”.
CLASSIFI CATION OF CAR TRIDGE
A.
According to the t ype of f irearms asked
1.
2.
3.
4.
B.
Revolver cartridges
Pistol cartridges
Rif les cartridges
Shot Cartridges
Used in revolver
Used automatic pistol
Used in r if les
Used in shot gun
According to location of primer
1. Pin f ire cartr idges no longer used (absolute)
2. Rim f ire – the prim er is located at the rim or the base
portion
-- Use in cal .22, pistol, revolvers and r if les
3. Canter f ire – Pr iming powder is locat ed at the center
-- Economical can be repealed
a. Rimmed t ype – Used in revolver s cal .38 and .35
b. Semi- Rimmed – Used in super .38
c. Rim less – Used in 45 pistols, Thompson, grease gun,
submachine gun
A.
TYPICAL RI MMED FIRE CARTRIDG ES
B.
A – Case
B – Prim ing mixture
C – Propellant powder/ gun powder
D – Bullet
E – Sensit ive Area
According to Caliber
1. cal .22 – used in revolvers, pistols and rif les
2. cal .25 – used in pist ols and rif les
3. cal .30 – used in carbine and other rif les
4. cal .32 – used in aut omatic pistols and revolvers
5. cal .380 – used in pistols
6. cal .38 – used in revolvers
7. cal .357 – used in .357 revolvers (magnum)
8. cal .44 – used in magnum revolvers
9. cal .44 – used in aut omatic pistols
10.
cal .50 – used in cal .50 machine gun (not use in
crimes)
Cal .30 bullet is replaceable by the bullet of cal .44
Shot gun Shel l
Single unit of ammo. f or shot gun
It is usually larger used in smooth bores capable withst anding f or
less pr essur e.
Paper Tube
Met al base
Base rod
Battery cap
Priming cap
Anvil
Priming Powder
Propellant
Over powder wa d
Filler wad
Shot
Closing wad
45-70 Cartridge
Contains 70 grains of gunpowder
Cartridge Lif e – a well made cartr idges have a lif e of 10 years some
have only 5 -6 years.
45 years or more – depend upon the sur rounding of the cartridge and
climate, damp, war n, condition.
Bullet / slugs
Is a metallic or non - metallic cylindrical projectile propelled f rom
a f irearm by means of expansive gases coming f rom burning gun
powder.
Slugs – laymen’s ter m – use in court dur ing proceedings
Projectiles propel led f rom a shot gun are termed shots or
pellets.
Iced Bullet – Super cooled water made as a projectile of solidif ied
bullets have a lif e of 3 minutes maximum
Hist or y – Bullet derive f rom a French word Boulette which means small
ball
In Government par lan ce a cartr idges containing bullet is called
Ball- Bullet
Ball – Comes f rom terminology of bullet
-- The core of the slugs is an alloy of lead, antimony and
sometimes t in.
Armor piercing bullet a core of tungsten chrome steel with continues
to penetrate armor cars af ter the jackets and the f iller have been
striped away by contract with the resistance surf ace.
CLASSIFI CATION
A.
According to mechanical construction
1. Lead Bullet – Those which are made of lead alloys of this mental –
lead, tin, antonym—which is slightly har der than pure lead.
2. Jacketed Bullets – Those which core of lead covered by jacket of
harder metal
-- The primar y f unction of the “jacket” in a bullet is t o prevent
adherent of metal (lead) to the inside of the gun barrel.
B.
According to shape
Flat Base
Boat Tailed
Square Base
Hollow Base
C. According to t ype/ common bullet t ype
Solid Lead
Solid Hollow point Solid Paper Metal Case point
Patched
Sof t
slug
Metal
Metal point Rif led
Bullet
case
Hollow point Metal point rif led
Gaypely
Bullet
Quadraximun Slug
KEY HOLE SHOT – The tumbling of a bullet in its f light and hitting the
target sideways as a results of spinning on its axis. (due to destroyed
barrel or loose barrel)
In generally .0002 s ec. explosion of
tremendous explosion of burning gases.
a
bullet
by
means
of
a
RESI STANCE of a .38 is 15, 000 to 45,000 m/pound
CONTACT W OUND – 4,8 inches – distance of the f ire with gunpowder
without the bur ning of the tissue means f irer is more than 24 i nches
Copper nickel ----- 60%
----- 40%
Gliding metal ------ 90%
----- 10%
8-4 inches
1-3 inches
Gun powder
Gun
Powder
Tattooing
Ta
Priming powder
powder
PURPOSE OF BULLETS
.38 Bullet --- disabilit y purpose – used by police of f icers to get
conf ession
.45 Bullet --- knocking subdue pur pose
M16 --- Fatal ef f ect
Garand and Carbine --- penetration, long range shoot ing
.45 Bullet --- Knowing Subdue Purposes
Rif led Bullets (5 Pr inc ipal Parts)
1.
2.
3.
4.
5.
Ball Bullets
Armored Piercing
Tracer Bullet
Incendiar y
Explosive (f ragmentation)
B.
All Bullets --- have sof t lead cores inside a jacket and are used
against personnel only.
Armored Piercing --- have hardened steel cores and are a f ired
against vehicle and other armored target is general.
Tracer Bullets --- contains a compound at the base usually sim ilar
barium nitrates which is set on f ire when the bullet is project ed.
--- The f lash of the smoke f rom the burning permits the light of
the bullet to be seen
In Cendiar y --- contains a mixtur e of such phosphorous and other
materials that can be set on f ire by impact.
---They are used against target tat will readily burn such as air
craf ts or gasoline depot.
Explosive ( Fragmentary) --- cont ai ns a high changed explosive,
because of their small size it is dif f icult to make a f use that will work
reliably in small size ammunition.
For the reason t he use of high explosive bullets is usually limited to
20 mm. and above.
Pointed Bullet --- is more ef f ective ballistically than the round ball of
the same weight
Sof t Point or Mushroom Bullet --- will expand on striking an object and
there f or produce much more serious check, and have corresponding
greater stopping power.
Hollow Point Bullet --- a bullet wit h a cavit y in the nose design to
increase the expansion when it hits the f orget.
Metal Cased Bullet --- colonially use to indicate either a met al patched
or f ull patched bullet .
Metal patched --- any metal patched bullet
Bullet having sof t steal j acket of ten clog or plated wit h gilding
metal to prevent rust ing and reduce f rictional resistance in the bore.
CARTRIDGES CASES/ SHELL
-- Is a tabular metallic or non -metallic container which old tog ether the
bullet, gunpowder and primer.
-- The cartridg e case is the portion of the cartridges that is
automatically ejected f rom the automatic f irearm during f iring and this
remains at the scene of the crime. This is a f irearm evidence than can
help trace part icular f irearms use.
FUNCTION:
1. It serves as a me ans whereby the bullet , gunpowder and primer
are assembled int o a unit.
2. It serves as a waster proof contained f or gunpowder.
3. It prevents the escape of the gases to the rear as t he sidewalls
of the cartridges cases are f orced against the walls of the
chamber by the pressure. It ser ves as the “gas seal” at the
breech end of the barrel.
PARTS
1. RI M – Ser ve the purpose of lim iting the f orward travel of the
cartridges into their chambers and this also lim it the clearance.
If any bet ween the heads and the suppor t ing surf ace of the bolt
or breech block.
2. PRI MER POCKET – Perf orms tipple f unct ion:
a. Holding primer securely in control position
b. Providing or means to prevent the escape of jobs to t he
rear of the cartridges.
c. Providing a solid support f rom primer anvil with out which
the latter could not be f ired.
3. VENTS OR FLASH HOLE – Is the hole in the web or bottom of
the primer pocket thought which the primer “f lash” impart
ignit ion to the pr imer charges.
The “opening” or “canal” that connects t he pr iming mixture with
the gunpowder.
4. THE HEAD – THE BODY – constitut e the “cork” that plugs t he
breech of the barrel against the escape of the gas.
5. NECK – That part of the cartridges case that is occupied by t he
bullet.
6. CANNELURES – ar e the separate grooves that are somet imes
f ound “rolled” into the neck and bodies of the cases at the
location of the bullets bases to prevent the bullet f rom being
pushed back or loosened.
7. CRI MP – Is that par t of the mouth of the cases tat is turned in
upon the bullet.
a. if aid in holding the bul let in place
b. if after resistance to the movement of the bullet out of the
neck which ef f ects the burning of the powder.
8. BASE – The port ion of case which contains:
a. The primer which contains the pr iming mixture
b. The shell head which contains t he head stamp caliber and
the year of manuf acture.
9. SHOULDER – That portion which support the neck.
10.
EXTRACTION GROOVE – The circular grooves near the
base of the case of shell designed f or automatic wit hdrawal of
the case af ter each f iring.
mouth
neck
shoulder
shell c annelur e
body
gun powder
vent
extracting grooves
rim
primer
shell head
CLASSIFI CATION
SHAPES)
ACCORDI NG
TO
CASE
SHAPE
(3
GEN.
A.
--- straight
--- all rim f ire shell and most center f ire
revolver cartridges that are new manuf actured
have straight cases.
B.
--- Tampered
--- is ver y rar e but presently being used in the
so called “magnum jet” cartridges cal .22
C.
--- Bottle neck
--- most modern center f ire rif le cartridges
case are of bottle neck types. Since this case
f orm provided t he greatest powder capacity
commensurate with over all case length.
STANDARD CARTRI DGES HEAD FORMS ARE:
A. RI MMED – designed to use in revolvers, the diam eter of the
base of the cartridges is ver y much bigger than the diamet er of
the body of the cartridges.
-- straight type cartridges
-- f ound in cal .30 (carbine) .32, .38 and .35
B. SEMI- RI MMED – designed to be used in automatic weapons like
pistols and sub -inact ive gums such as super .38 uz1, 9mm.
-- normally f ound at the cr ime scene because they
are automatically ejected f or easy f irin g of the
f irearm.
C. RI MLESS – case within the diameter of the body of the
cartridges is the sam e as the diameter of the cartridges case.
-- Use in automatic pistols such as cal .45 thompson Sub machine gun and cal .45 grease gun.
-- Automatically ejected li ke semi-rimmed type.
PRI MERS
-- Is that port ions of the cartridge which consist of the brass
gilding metal-cup containing a highly sensitive mixture of chemical
compound, which when struck by the f iring pin would det onate or
ignite. Such act ion is calle d Percussion.
-- Use f or igniting the gunpowder, a blow f rom the f iring pin on
the primer cup compresses t he pr iming mixture and this causes the
composition to detonate on explodes. This detonat ing on explosion
produces “f lame” which passes through t he “e vent” on “f lash hole” in
the cartridges case and this ignites the gunpowder.
ORIGIN
-- 1807 – Alexander John Forsyth
-- First one t o conceive the idea of using detonat ing compounds
f or igniting powder charges in small arms by percussion.
-- A scotch Pr esbytorian minister chem ist and hunter.
-- A well known authorit y on f irearms
-- First successf ul prim ing mixture was one composed of
Potassium chlorat e, charcoal and sulf ur in powder f orm.
PARTS:
In a typical center f ire cartridges have f our parts
1. PRI MER CUP – container of the priming mixture made up of
brass, gliding metal or copper.
2. PRI MI NG MIXTURE – highly
contained in the primer cups.
sensitive
chemical
mixture
3. ANVI L – t hat portion of the pr imer against which the prim ing
mixture is cr ushed by a b low f rom the f iring pin. To provide t he
resistance necessar y to f ire the pr iming mixture.
4. DISC – piece of small paper on disc of the pin, f oil which is
pressed over the pr iming mixt ure.
Two f old purposes
a. to help hold the pr im ing mixture in place
b. to exclude moisture
1. primer cup
2. priming mixtur e 3. anvil
4. disc
PRI MI NG CO MPOUNDS: Classes
1.
Corrosive primers – e.g Potassium chlorate – if ignited produce
potassium chloride, draws moist ure f rom the air and t his
moisture speeds the rusting and corrosi on in gun barrel.
Advances in chemistry produce new composition which
potassium chlorate has been eliminated.
Non-corrosive – every manuf acture has his own f ormula mixt ure
of the mercuric prim ers of 25 years ago.
Ingredients:
2.
-
Potassium chlorat e (initiato r and f uel 45%)
Antimony Sulf ide (elements and f uel 23%)
Fulm inat e way came the standard mixt ure by Frankf ord
Arsenal known as FH -24 had the f ollowing composit ion:
- sulf ur
- 21.97%
- Potassium chlorate
- 47.20%
- Antimony Sulf ide - 30.33%
-
-
-
German have their own composition bar ium nitrate in the
place of Potassium chlorate together with some Picr ic
Acid to strengthen mixture.
This f ormula:
Fulm irate of mercury
- 39%
Barrium nitrate
- 41%
Antimony Sulf ide
- 9%
Picr ic Acid
- 5%
Ground glass
- 6%
Swiss Arm y has been using non -corrosive primer since
about 1911. This was base on the f ormula of a Swiss
inventor named ZIEGLER: Swiss f ormula.
Fulm irate of mercury
Barrium nitrate
Antimony sulf ide
Barrium carbonate
Ground glass
-40%
-25%
-25%
- 8%
- 4%
GUN POW DER
Is the pr opellant which when ignited by the primer f lash is
converted to gas under high pressure and this propels the bullet or
shot changes through the barrel and on t he target.
Class or Composition:
1. BLACK Powder – although if featur es loss important still
manuf actured by t he Europeans. In recent time has completely
superseded by smokeless powder.
Ingredients:
Potassium nitrate -75%
Sulf ur
-10%
Charcoal
-15%
Produces grayish smoke and considerable residue is lef t in the
barrel.
Burns with reasonable great rapidit y when ignited.
Block Powder – r elies f or its explosive pr operties on 3 quant it ies
which are t ypical of all explosives
FIRST – when ignit ed it will burn by it self without aid f rom the
outside air.
SECO ND – in burning, it gives of f a large amount of gas.
THIRD – a considerable amount of heat is evolved.
2. SMO KELESS PO W DER – terms smokeless powder is misnomer
f or the are neither powder nor they are smokeless. The letters
terms term being applied to t hem only because th ey do not give of f
huge cloud of white smoke like the black powder.
Two main Classes of smokeless powder
1. SINGLE – BASE PROPELLANT OR NITROCELLULOSE
-- contains only t he pure nitroglycer ine gelator iged with
nitrocellulose
2. DOUBLE – BASE PROPELLANT
-- composed of nitrocellulose and nitroglycer ine as
their major ingredients according by one more ingredients
such as:
a. Centralize
b. Vaseline Phthalat e esters
c. Inorganic salt
Purpose of minor ing redients
a: Insure stabilit y
b. Reduce f lash or f l ame temperature (or both)
Double – base Propellant are gray green color and the grains are
similar in size and shape to the single – base propellants.
Almost all smokeless powder grains have perf ectly def inite shape
such as
a. small squares
b. disc
c. f lakes
d. strips
e. pellets
f . perf orated cylindrical grains
The powder is made in dif f erent shapes to obtain certain t ypes of
burning.
SCIENTIFIC EQUIPMENTS GENERALLY USED IN FIREARMS
IDENTIFICATION
1. Bullet Compar ison Micr oscope
A piece of opt ical equipment f requently employed by f irearms
identif icat ion expert is the bullet com parison microscope, with
camera attachment.
2. Stereoscopic Micr oscope
No camer a attachment and no photomicr ograph can be taken f or
court tampered serial number.
3. Shado wgraph
A ser ies of microscopic lenses of dif f erent magnif ication use to
determine class characterist ics of f ired bullets and shells.
Also f or orientation purposes.
It can take phom igrograph of the obser vations and compar isons
made in the circulation groun d glass.
4. CD-6 Compar ison Pr ojector
Ver y much similar with the bullet compar ison microscope
No eyestrain because the magnif ied image appears on the large
screen. W hat can be seen in the screen can be photographed by
any kind of camera.
5. Bullet Recover y Box
Long box (12” x 12” x 96”) f illed wit h ordinar y cotton and
separated into sect ions by and board part itions.
6. Helixometer
Used in measur ing “pitch of rif ling”. Distance traveled by the
bullet in one complet e rotation.
7. Micrometer
Sim ilar in use as caliper
8. Caliper
Use f or making measurements such as bullet diameter bar rel
length.
9. Analytical or torsion balance
Use to determ ine weights of bullets and pellets f or possible
determination of type, caliber and make f rom which f ired.
10.
On scope
Small instrument som etimes used in examining the inter nal
surf ace of the gun barrel in determ ining the irregularit ies inside
the bore of the gun barrel. It has a tiny lamp the terminal por tion
and is inserted inside the bore f or internal examinations.
11.
Taper Gauge
Use pr imari ly f or determining bore diameter.
12.
Electrical Gun Maker
Used in the laborat ory f or making f ired bullets f ired shells and
f irearms submitted f or examination.
TECHNIQUES OF EXAMINATION
PHYSICAL: Evidence bullets, cartridges cases and suspected f irearms
once subm itted by t he requesting part y will be physically examined to
determine its markings or initials will be physically examined t o
determine its markings or init ials made by the investigators f or
identif icat ion purposes.
TEST FIRING:
The f irearms is tes t f ired from a bullet recover y box
in order to obtain test bullets and test cartridges cases f or comparison
with evidence bullets and cartridge cases, but bef ore f iring the
cartridge will be marked at the side of the case on the nose portion of
the bullet with letter T (test) f ollowed ( eg T -77-1 to T -77-3) in their
order of f iring to dist inguish the number 1 test f rom 2 and 3. Af ter the
recover y of the test bullets and test cartridges cases, they will be
compared with the evidenced bullet and evidence cartr idges cases,
under the bullet comparison micr oscope to determ ine whet her or not
they have the congruency of striat ions or t he same individual
character ist ics.
Under the bullet comparison microscope, the t wo f ired bullets or f ired
shells are examine in a J UXTAPOSITION - That is, the t wo object evidence and the test bullet are examined and compared:
1.
2.
3.
4.
5.
at
at
at
at
at
the
the
the
the
the
same
same
same
same
same
time
place or level
dir ect ion
magnif ication
image
For conclusiveness of f indings, t here shall be at least 3 test bullets
that should be compared
First 1 f or Comparison/ prelim inar y
Second 1 f or conf irmation
Third 1 f or conclusion
PERI PHERY
These are the sides of the bullet are in contact with the inner
surf ace of the barrel.
STRIATIONS
A individual charact erist ics of the cartr idges f ound at the base
portion and of the side of the bullet come in cont act with the inner
surf ace of the barrel.
TEST BULLETS
Are those r ecovered f rom bullet recover y box f or a comparison
with the evidenced bullets under the bullet comparison micr oscope.
A f ired or evidenced bullets or cartridges cases are those r ecovered
f rom the crime scene.
Interconnected or int ermarriages 8 or more striations can be accepted
by the court.
3 Points of basic positive ide nt if ication the markings must be:
1. Prominent
2. Signif icant; and ar e
3. Consistent
Means of –test f iring, other than the recover y box.
1.
2.
3.
4.
W ater tank
Saw dust with oil
Sand
W aste threads
5. Darak
6. Banana trunk
7. Rubber trips
PRINCIPLES I N F IREARMS I DENTIFICATION
Two things mark by one and same tool will bear the same markings,
likewise t wo or more things mark by dif f erent tools will have the same
markings.
DEFI NITIONS
PISTOL – a hand f irearm usually applied to simple sot and automatic
loading.
REVOLVER – a hand f irearm in which a r otating cylinder successively
-- places cartridges into posit ion f or f iring.
SHOTGUN – a smooth-bore weapon designed to shoot a number of
lead pellets in one charge.
RIFLE – a type of weapon designe d to be f ired from the shoulder.
CARTRIDGE – ter m used to describe a complete unf ired unit
consisting of the bullets, primer cartridges case and powder charge.
BULLET – is a projectile propelled f rom a charge.
AUTO MATIC – a weapon is automat ic when its m echanism is so
arranged that it will f ire cont inuously while the trigger is depr essed.
DOUBLE ACTION – weapon in which pressure upon the trigger both
cocks and release the hammer.
SINGLE ACTION – weapon in which pr essure upon the tr igger release
the hammer that must be manually cocked.
CALI BER – term used to indicate t he bor e diameter which is measured
bet ween t wo opposit e lands.
GAUGE or GAGE – as applied t o shotguns, it indicates that the bore
diameter is equal to the diam eter of a lead ball whose we ight in
pounds is equal to the recipr ocal gauge index.
Ex. bore diameter of a lead ball weighing 1/12 of a pound.
BORE – the cylindrical passage of the barrel through which the
projectile travels.
PITCH OF RIFLING – the distance that the rif ling advance s to make
one complete tur n.
EXPERT – as used in, court includes all witnesses whose opinions are
admitted on grounds of specialized knowledge, training and
exper ience.
BREECHBLOCK – t he steel block which closes the rear of the bore
against the f orce of charge or that part in the breech mechanism that
locks the act ion against the f ir ing of the cartr idges; the f ace of this
block is known as the breech f ace.
CHAMBER – that part of the weapon in which the cartridge is placed
into posit ion f or f iring.
EJECTOR – that mechanism in a f irearm which causes the empty shell
or ammunit ion to be thrown out f rom the gun.
EXTRACTOR – t hat mechanism in a f irearm by which the empty shell
or ammunit ion is wit hdrawn f rom the chamber.
GROOVES – the depressed channels cut in the inter ior of a rif led gun
barrel.
LANDS – that raised portion bet ween t he grooves inside a rif led gun
barrel.
VELOCITY – is the f or ward speed at which the bullet travels measured
in f eet per second.
PRESSURE – the outward thrust of the burning pow der gases against
the breechblock, chamber and bore nor mally measured one inch f rom
the breech and recor ded in pounds per square inch.
Ex. 14,000 to 15, 000 pounds per square inch f or caliber .45 automatic
pistol.
RANGE – the straig ht distance bet ween the muzzle of the gun and the
target.
PENETRATION – the depth to which a pr ojectile sinks in the t ar get.
Ex. 6 inches at 15 yards in white pinewood.
TRAJECTORY – in t he actual pattern or curved pat h of the bullets in
f light.
FIRING PIN – that part of that f irearm which strikes the prim er causing
the f iring of the cartridge.
HAMMER – that part of the f irearm controlled by the trig ger which
causes the f iring pin to strike the primer striking the gun.
CORROSION – the chemical eating away of the bore of an a r m due to
rusting or the act ion of salts deposited f rom they cap or powder.
EROSION – mechanical wear and tear of the bore of an arm due to
sliding f riction when the bullet passes through it.
BERDAN PRI MER – a primer with t wo f lash holes or vents.
BOXER PRI MER – a primer with only one f lash hole or vents.
RI M – the projection edge of the base or head of a certain car tridge.
OGIVE – is the technical name of the cylindr ical head cr itic of the
bullets.
BREECH end – the rear end of the bore of an arm wher e the
cartridges is inserted.
PANG ASINAN COLLEGES OF SCIENCE AND TECHNOLOGY
COLLEGE OFCRI MI NOLOGY
Urdaneta Cit y
NO TES I N PERSO NAL IDENTI FIC ATION
BRIEF HISTO RY OF FINGERPRINTING
In tracing the origin of the f ingerprint science we must draw a
dist inct ion bet ween the realizat ion that the tips of the finger bear
diversif ied r idged and the application of the knowledge to the problem
of personal identif ication.
Unquestionable, men’s consciousness of the patterned r idges on his
f ingers and palms predates the Christ ian era by many cent uries and
has been evidenced in var ying degrees by successive civilizations. On
the f ace of a cliff in Nova Scotia, for instance, has been f ound
prehistoric India “picture wr iting” of a hand wit h ridge patter ns crudel y
marked. Scholars ref er to the impression of f ingerprints on clay tablets
recording transact ion in Ancient Babylon and t o clay seals of Ancient
Chinese or igin bearing thumb pr ints. Apostles Paul concludes one of
his epist les wit h the words. “The Salvat ion a Paul with mine own hand
which is the token in ver y epistle; so I wr ite.” Some have inf erred f rom
these words that Paul used his f inger impression as a distinctive
signature. Chinese documents ident if ied with t he eight cent ury ( A.D)
T’ and Dynasty ref ers to f ingerpr ints being increased upon business
contracts, and the Chinese Monarchs termed fingerprint as Hua Chi
It is conjectural to what ext ent these earlier instance of f ingerprints
were intended f or actual identif icat ion of the persons impr essing the
prints. Cert ainly in some cases the object was simple to add more or
less superst itious solemnit y to business contracts trough the personal
contact of the contracting parties f ingerprints with the written record.
Their evidence, however that f act of the individualit y of f ingerprints
though not put to pr actical use dr owned recurrent ly through the ages.
In f ourteenth century in Persia, various off icial government papers
were reportedly impr essed either f ingerprints, and the obser vation was
made by a government off icial who was also a physician that no
finger prints of two persons were exactly alike.
In 1684, Dr. Nehemiah Grew , a f ellow of the Royal College of
Physicians, in the course of a lecture commented upon t he r idge
patterns appearing on the f ingers. But if any of these early adventures
in f ingerprints obser vat ion had any direct inf luence on the men who
are the f athers of the modern science of f ingerprints identif ication, the
known record does not ref lect it.
A scient if ic approach to f ingerprint was essential bef or e it could be put
practical use on any extensive scale. The outline which f ollows begin
with what are believed to be the f irst scientif ic obser vations which m ay
reasonably be supposed t o have contributed t o the inception of
modern f ingerprint identif icat io n. These obser vat ions were in:
1686 – by Marcello Malpighi , Prof essor of Anatomy at the Universit y
of Bologna, Malpigi, making use of a newly discovered, microscope,
noted and discussed in his treaties “certain elevat ed ridges”
descr ibing “diverse figures ” on the palm surf aces.
He perceived them t o be “dr awn int o 1686 and spiral” at the end of the
f ingers.
Appar ently the signif icance of his obser vat ion escaped him, however,
f or he purposed them to f urther. More t han a centur y elapsed, and it
was not unt il, 1823 that John Evangelist Purkinje , Prof essor of
Anatom y at the Universit y of Breslau, published a thesis in which he
commented upon the diversity of ridged patterns “especially on t he
last phalange of each f inger and evolved a vague dif f erentiat ion of
these patterns into nine varieties. Purkinje’s paper was intended only
as a scholarly treaties and had no practical application to the problem
of personal ident if ication, but thirt y years later, in 1858 Sir William
Herschel, the Br itish Chief Administr ati ve off icer f or the Hooghly
distr ict, Bengal, India, began the f irst known off icial used of
f ingerprints on large scale. He req uired natives to aff ix their
f ingerprints as well as their signature to contracts.
Appar ently he had no idea originally that the marks were individual but
adopted the pract ice with the thought that this ver y personal t ype of
contract wit h of f icial papers would be impressed to the native m ind
and would discourage, dishonest y and def ault.
A f amiliarit y wit h f inger impressions grew; h owever, their individual
must have become evidence to him, f or in 1877 Herschel introduced
the use of f ingerprints in gener al departments at Hall and also
submitted report asking permission to extend the practice as a means
of identif icat ion of prisoners a s well as parties to civil contracts. The
permission was not forthcoming but Herschel, within his own province,
applied the system extensively. He did not, however, evolve a method
of classif icat ion suit able f or general use.
At about this same time, Dr. Henry Faulds, of Tsukiji Hospital in
Tokyo, Japan, beg an his obser vation of f ingerprints. The English
scientif ic jour nal, “Nature” in 1880 published an art icle by Dr. Faulds,
discussing his studies and making suggestions as to the f uture
possibilit ies of th e f ingerprints sciences. His ideas are remar kable f or
their ant icipat ion of present day practice. He recommended t he use of
a thin f ilm of printer ’s ink as transf er medium just as it gener ally used
today. He discussed quite f ully the potentialities of iden t ificat ion of
criminals by their f ingerprints lef t at the scene of crimes, just as in the
modem science of latent f ingerprint identif ication. As a matter of f acts,
Faulds, himself , demonstrated the practical application of his theor y
establishing through g reasy f ingerprint marks the identit y of a person
who had been dr inking some spir its f rom the laborator y supply --certainly one of the earliest latent f ingerprint identif icat ion of modem
times.
1882 – is the year in which appears the f irst authenticated re cord of
off icials use of f ingerprints in the United States. Mr. Gilbert Thompson
of the United States Geological Sur vey, while in change of a f ield in
New Mexico, used his own f ingerprint on commissar y orders t o prevent
their f orgery.
An interest ing sidel ight, which had possible ef f ect on the introduction
of f ingerprint ident ificat ion into the Unit ed States, occurred in 1883
with the publication of Mark Twian Lif e in the Mississippi. An episode
in this book relates to the identif icat ion of a murdered by hi s thumb
print. Mark Twian f urther developed his theme ten years later in 1893
with the publication of “Pudd’n head W ilson”, novel plotted around a
dramatic f ingerprint ident if ication demonstrated dur ing a court trial
and including a str iking exposit ion of the inf allibilit y of f ingerprint
identif icat ion, the more remarkable because of the dates its
publication.
It was also in the 1880’s that Sir Francis Galton, a not ed Br itish
Anthropologist
and a cousin of scientist, Charles Dar win, began
obser vat ions whi ch led to the publication, 1892, of is book, “Finger
Prints”. Galton’s studies established the individualit y and permanence
of f ingerprints and he made another important contribution by devising
the f irst scient if ic method of classif ying f ingerprint patter ns.
1891 – marked the f irst installation of fingerprint f iles as an off icial
means of criminal identif icat ion . Juan Vucetich, an Ar gentinean
police of f icial, based his syst em on the patterns t yped by Bertillon
system of identif ication by body measurement s, which it gradually
replaced. The Vucet ich system is the basis of those systems present ly
used in most Spanish speaking countries and a number of the
countries as well Vucet ich also claim ed the f irst off icial criminal
identif icat ion by means of f ingerpri nts lef t at the scene of a crime.
1892 – At La Plata, Argentina, a woman named Rojas, who murdered
her two sons and cut her own throat, through not f atally, blamed the
attacks on a neighbor. Bloody f ingerprint on a door post wer e
identif ied by Vucetich as those of the woman herself and led to her
conf ession.
1901 – marked the off icial introduct ion of f ingerprint f or criminal
identif icat ion in England and Wales, the system employed was also
developed f rom Galton’s obser vation and was devised by Sir Edward
Richard Henry , t he inspector General of police in Bengal. Henr y
simplif ied f ingerprint classif ication and made it applicable to police
identif icat ion, and later on Sir Edward Richard Henr y was cr edited as
the f ather of f ingerprint science.
1902 is the yea r in which the f irst known systematic use of f ingerprints
in t he United States was begun with the establishment of the pract ice
of f ingerprints by the New York Civil Com mission to Prevent applicants
f rom having better qualif ied persons takes their tests f o r them. Dr.
Henry P. De Forest , an American pioneer in the f ingerprint science,
installed the system in December 1902.
1903 is claimed by the New York State prison system as the date of
the f irst pract ical, systematic use of f ingerprints in the United Sta te f or
the identif icat ion of criminals.
As early as March of this year, f ingerprints of prisoners were taken
and classif ied and on June 5, the f ingerprint system was off icially
adopted.
1904 f ound acceptance of the f ingerprints system accelerated when
the United St ates Penitentiar y at Leavenworth, Kansas, and the St.
Louise Missour i Police Department both established f ingerprint
bureaus. The St. Louise bureau was inaugurated with the assistance
of a Sergeant of London’s Scot land Yar d who was on dut y at th e St.
Louise Exposit ion g uarding a Brit ish exhibit. The Leavenworth bureau
become the f irst to off er f acilit ies on m ore than a local basis when it
gradually expanded the scope of its operat ion to include a free
f ingerprint exchange service among a growing list of contribut ion
peace off icers.
During the f irst quar ter of the 20 t h Century mor e and mor e local police
identif icat ion bureaus established f ingerprint systems and many sent
copies of their f ingerprint recor ds to the National Bureau of Criminal
Identif icat ion
established
by
the
International
Identif icat ion,
Associat ion of chief of Police. The obvious need and demand by police
off icials led to an Act of Congress establishing on July.
1924 the ident if ication Division of the FBI. The f ingerprint records of
both the National Bureau of Criminal Identif ication and of Leavenworth
Penitent iar y, totaling 810, 188 were consolidated to f orm the nuclear
of the FBI f iles. The national repositor y of criminal investigation dat e
quickly proved its worth to law enf orce ment off icials f aced with
problems of criminals moving rapidly f rom cit y to cit y and state to
state. Addit ional ser vices were added in the FBI identif icat ion Division
as the need becam e apparent, on Mar ch 1, 1932. The Int ernational
Exchange of f ingerprints date was initiated with a number of other
nations, on Februar y 15, 1932.
1933 – A Latent f ingerprint Section f or making technical examinat ion
of latent prints or of inked pr ints on an individual basis, was instituted.
On November 10 of the same year the Civil Identif icat ion Section was
established. A steadily increasing rate of receipts brought the number
of f ingerprints cards in FBI f iles to 10 million. In 1939, but it was the
exigencies of wor ld II tat brought about the phenomena per iod of the
identif icat ion Divisions growth.
Drawing the years j ust bef ore and dur ing the war, t he number of civil
f ingerprints, including of aliens, milit ary personnel and civilian
employees in def ense industries, f ar out stripped the number of arrest
prints. Both t ypes t oget her added to the swelling total unt il Januar y
31.
1946 – t he 100 millionth f ingerprint card use was received in the
Identif icat ion Division of the FBI, the world’s largest repositor y of
f ingerprint records. Although new met hods of personal identif ication
are constantly being suggested even today, it is har d to conceive of a
system being devised, which can impr ove upon the combinat ion of
f acilit y, pract ically, and inf allibilit y, which is characteristic of the
f ingerprint system. As of Januar y 1,1959. The to tal had grown to over
152,000,000 records as of May 11,1959.
3 BR ANCHES OF DACTYLOSCOPY
1. Chiroscopy – It is an allied science of dactyloscopy which deals
with the scient if ic examinat ion of the palm of the hand
2. Podoscopy- A branch of science of dactylosco py which f ocused
on the scient if ic examinat ion of the sole of the f oot.
3. Poroscopy- Allied br anch of dact yloscopy which deals with the
study of the sweat pores f ound in the f riction skin.
Three (3) fundamentals fact s that have made Fingerprint a
superlati ve method of the indi vi dualization of person. ( Doctrines
of fingerprint identification)
1. Perennialit y- An individual f ingerprint ridges are f ormed during
the f etal lif e 100 -120 days (3-4 mos) inside the womb of the
mother and remain unchanged f or the remai nder of person
lif etime.(Gods given)
2. Inf alliabilit y-It
has
been
shown
empirically
(based
on
exper ienced and obser vat ion) wit h theoretical support, t hat
f ingerprint are unique (one of its kind) no t wo person possess
the same ridge char acterist ics.
3. Immutabilit y – it has been proven that the f ingerprint of a person
are unchangeable, you cannot change the f ingerprint of Any
individual.
THE PRI NCIPLES OF THE SCI ENCE OF D ACTYLOSCO PY
1. It is the only inf alliable system of identif ication
2. it is the most convin cing proof s to mans individualit y
3. it enable to unmask the real ident it y of the law breaker
Fingerpri nt as a science - it is an identif icat ion of a person
through the used of ridges appear ing in the f inger of the palm of
the hand and sole of the f oot
Fingerpri nt as an impression - It is the reproduction of some
surf ace of the pattern f ormed by the r idges on t he f irst joint of the
f inger.
Tw o (2) types of fingerprint impression
1. Rolled impression- Rolling the fingers
2. Plane impression- No need to roll the finger you just dent the finger
including the thumb.
RULES GOVERNI NG THE CHOICE BETWEEN TWO OR MORE
POSSIBLE DELTAS.
1. The delta may not be locat ed at a bif urcation, which does open
toward the core.
2. W hen there is a choice bet ween a bif urcation and another t y pe
of delta, the bif urcation is selected/ chooses.
3. W hen there are t wo or more possible deltas, which conf orm to
the def init ion the one nearest the core, is chosen.
4. The delta may not be located in the middle of a r idge running
bet ween the t ype line toward t he cor e, but at the nearer end
only.
RULES I N THE SELECTION OF CO RE O F A LOOP:
1. The core in placed or within the innermost suff icient re -cur ves.
2. W hen the innermost suff icient re -cur ve does not cont ain any
ending ridge or r od, the cor e is placed on the sho ulder of a loop
f urther f rom the delt a.
3. W hen the innermost suff icient re -cur ve contains odd number of
rod, the core is placed upon the tip of the outer rod.
4. W hen the innermost suff icient re -cur ve contains even number of
rod, the core is placed upon the end of one of the two center
rods f urther f rom the delta.
INTERPRETATION OF FINGERPRINTS:
Three basic types of pattern are as f ollows:
Percent age of appearance
1. Arch
2. Loops
3. W horls
5%
60%
35%
The three basic types of pattern are f urther subdivided into the
f ollowing:
1.
2.
3.
4.
Plain arch
Tented arch
Radial loop
Ulnar loop
5.
6.
7.
8.
9.
Plain W horl
Central pocket loop
Lateral pocket loop
Double loop/t win loop
Accident al Pattern
RIDGE CO UNTI NG:
The number of ridg es inter viewing the delta and the cor e is
known as the ridge count. Ever y ridge t hat crossed or touched by the
imaginar y line bet ween the core and the delta, neither the delta/ core
is counted r ed line upon the r idicule of the f ingerprint glass is used t o
insure absolut e accuracy. In the event there is bif urcation of a ridge
exactly at the point where the imaginary line would be dr awn, t wo
ridges are counted. Fragments and dots are counted as r idges if they
appear to be thin and heavy as t he ridges in the immediat e pattern.
Variations inking and pressure must of course be considered.
TYPES OF FI NGERPRINT P ATTERNS
1. PLAI N ARCH
A type of f ingerprint pattern where the majority of the ridges came
f rom one side then f low to the other side with the slight rise at the
center. It has no delt a and cor e.
2. THE TENTED ARCH
In the tented arch, most of the ridges enters in one side of the
impression then f low or tend out upon the other side with a r ise at the
center giving 90 degrees more or less and with a pres ent of up thrust.
It has no delta and core.
Three types of tented arches:
1. The type in which ridges at the center form a def inite angel: i.e.
90 or less
2. The type in which one or more ridges at the cent er f orm an up
thrust is an ending ridge of any le ngth rising at a suff icient
degree f rom the horizontal plain, 450 degree or more.
3. The type approaching the loop t ype possessing two of the basic
or essent ial char acteristics of the loop, but lacking the thir d.
The arches and som e of the loop are of ten con f used. It should be
remembered that the mere converging of two ridges does not f orm a
re-cur ve, without which there can be no loop. In the other hand, there
are many patterns which at f irst sight resemble tented arches but
which on abuse inspection are f ou nd to be loop, as when one looping
ridge will be f ound in an almost vertical position wit hin the pattern are
entirely f ree f rom and passing in f ront of the delta.
ULNAR LOOP
A Type of fingerprint pattern, which possesses a delta, core, and one or more
ridge forming a sufficient recurve within the pattern area. The slope or
downward flow of the innermost sufficient recurve is towards the little finger or
to the ulna bone of the hand of origin.
RADIAL LOOP
A type of fingerprint pattern, which possesses one delta and one core, and
one or more ridges within the pattern area, formed a sufficient recurve. The
flow of the innermost ridges is towards the thumb or to the radius bone of the
hand of origin.
THE PLAI N W ORL
The plain has t wo deltas and one co re and at least one r idge
making a complete circuit, which may be spiral, oval, circular or any
var iant of a circle. And when an imaginar y line drawn bet ween the t wo
deltas it must touch or cross at least one of the re -curving ridges
within f orming a com pl ete circuit wit hin t he pattern area. A r e -cur ving,
however, which an appendage connect ed with it in the line of f low
cannot be construed as a circuit. An appendage connect ed to the
points is consider ed to spin the re -cur ve on that side.
CENTRAL POCK ET LOOP
The central pocket loop t ype of whorl has t wo deltas and least
one r idge making a complete circuit, which may be spiral, oval,
circular, or any variant of a circle. An imaginar y line drawn bet ween
the two deltas must not touch or cross any of the recur ving ridges
within the inner pattern area. A recur ving ridge, however, which has
an appendage connected within the line of f low and on the delta side,
cannot be construct ed as a circuit. An appendage connected at that
point is considered to spoil the re-cur ve on that side.
On lieu of re -curve in f ront of the delta is the inner pattern area;
an obstruct ion at the right angle to the line of f low will suf f ice.
It is necessar y that t he inner line of f low be f ixed artif icially. The
inner line of f low is d etermined by drawing a line bet ween the inner
delta and center of the innermost re -cur ve or looping ridge.
DOUBLE LOOP
The double loop consists of two separate loop f ormation with
two separate and distinct sets of shoulders and t wo delt as.
The wor ld “separate” as used here, does not mean unconnected.
The two loop may be connect ed by an appending ridge provided aid. It
does not turn about at the right angle bet ween the shoulders of the
loop f ormation. The appendage rule f or the loop applies also to the
double loop.
The f act that there must be two separate loop f ormation
eliminates f rom consideration as a double loop the “S” t ype core, the
inter locking t ype core, and the f ormations with one loop inside
another.
It is essential that both sides of a l oop be equal length, nor that
the two loops be of the same size. Neit her is it materials f rom which
side the loop enters.
LATERAL POCKET LOOP
A type of fingerprint pattern in which the core ridges of the two loops makes
their access or exit on the same side of the fingerprint impression.
ACCIDENTAL W HORL
The accident al whorl is a patter n consisting of a combinat ion of
two dif f erent types of pattern with the exception of plain arch, wit h t wo
or more deltas; or a pattern, which possesses some of the
requirements f or t wo or more diff erent types; or a patter n, which
conf orms to none of the def init ions. It may be a combination of loop
and tented arch, loop and whor l, loop and whorl, loop and central
pocket loop, double loop and central pocket loop or other com bination.
The plain arch is excluded,
FINGERPRI NT CL ASSIFIC ATION SYSTEM (Henry system w ith FBI
modification and extension)
Sir, Edward Richard Henr y – Simplif ied the use of f inger print and
made it applicable into police works
Mr. A.J Renoe- Superintendent of the U.S dept of justice f ingerprint
bureau (1920), the Bureau was located in the Penitent iar y
Leavenworth, Kansas. He devised what was known as the A.J Renoe
Extensions and modif ication.
W illiam Burns - Head of U.S secret servic e (1924) he made division
and accumulat ion of f ingerprint record cards into suff iciently small
groups.
J. Edgar Hoover - Devised f urther extension, which in tur n have been
revised f rom time to time until present. He made an adequate f ile
containing many mi llion of f ingerprint.
Note: The entir e plan or f urther revision is based on the Henr y System
of classif icat ion.
Division of Classification – the classif ication f ormula is divided into
six possible divisions under
the extension system:
a) Primar y classif ica t ion
b) Secondar y classif ication
b.1 Capital letter groups
b.2 small letter groups
c) Sub-secondar y classif ication
d) Major classif ication
e) Key classif icat ion
f ) Final classif icat ion
Classification- The method of attaining a f ormula in a set of f ingerprint
placed in t he f ingerprint record cards
Classification Form ula - The numer ical descr ipt ion in a set of
f ingerprints which is composed of lett ers and f igures wr it ten above
and below the classif ication line.
Classification line - Ref ers to a long line which is usually p laced on the
right upper corner of the f ingerprint card or chart where classif ication
f ormula is wr itten.
The posit ions in the classif ication line f or these divisions when
complete applied are as illustrated.
K.C
M.C
P.C
18
L
29
S.C
rW 2u
S.S.C
F.C
MO I
5
I
5
Xt
OIO
a. The Primary cl assi fication – the pr im ary classif ication is the
numerical value of the whor ls in a set print. The arbitrar y value
assigned to the f ingers f or this purpose is as f ollows:
W hy do we have a pre -established f raction of 1/1?
a. T o give the number ed value group a place in the f ile
b. Zero over zero might be mistaken as outer over outer in
f iling
Blocking- Is the process of writ ing below each f inger print pattern the
corresponding symbol of its name.
Patterns as to numerical value
a. Pattern with numerical value – all whorl
b. Pattern without numerical value- arches and loops
Four stages to obtain primary classification
1. Pairing- 10 fingers are divided in 5 pairs
Finger
Finger
Finger
Finger
Finger
# 1 and # 2 -- ------------- 16
# 3 and # 4 -- ------------- 8
#5 and # 6 --- ------------ 4
#7 and #8 ----- ------------ 2
#9 and #10 -------------- 1
2. Assigning numerical value
3. Knowing the num erator and denom inator - The f irst pattern of ever y
pairs are the denominator (odd f ingers; 1,3,5,7,9) while t he second
pattern of ever y pair is the numer ator (even f ingers 2,4,6,8,10)
4. Summing the num erical value or values assigned to whorl plus the
pre-established f raction of 1/1
The sum of numerical value of whorls if any, in f ingers 1,3,5,7 and
9 with one added is the denominator of the pr imar y classif ication. The
sum of the numer ical value of the whor ls, it any in, 2, 4, 8 and 10, wit h
one added, is the numerator of the prim ary classif ied where no whorl
appears in a set of i mpressions, the primary, theref ore, would be 1/1/.
It is noted that 10/24 possible pr imaries may be obtained 1/1 to 32/32,
which is the pr imar y when whor ls appear in ever y f inger.
b. Secondary Classification - The secondar y classif ication is based
on the t ypes of patterns appearing on the index f ingers. Each f inger is
represent ed by capital and small lettered symbols
Secondar y classif ication by capital letter ed group - This is done
by exhibit ing the capital; letter symbol of the individual t ype of
patterns f rom the two index f inger af ter the primary
classif icat ion.
Right index f inger – Numerator
Lef t index f inger – Denominator
A symbol of the f ollowing symbol may come out
A – Plain arch
T – Tented arch
R – Radial loop
U – Ulnar loop
W – Plain whor l
C – central pocket loop
D – Double loop
X – Accidental Pattern
Secondar y classif ication by small lettered groups - the secondar y
classif icat ion by small lettered ref ers to the 3 t ypes of
f ingerprint patterns that can be exhibited by small lett ered
groups.
- It can be applied to all f ingers with a said patterns except
the t wo index f ingers
Radial loop – r
Plain arch - a
Tented arch- t
c. Sub-secondary classification - it is based upon the r idge count or
ridge tracing in the index, middle and ring f inger s
Ridge count ing ref ers to loops pattern while r idge tracing ref er
to whor l patterns .
Ridge count – ref ers to t he tot al number of ridges intervening
bet ween the delta and the core (delta and core are not included in the
count ing)
Tables f or symbols of loops as a result of ridge count
1. A ridge count of 1 -9 inclusive of the two index f inger is
deduct ed int o symbol capital letter I f or inner, while 10 or
more O f or outer.
2. A ridge count of 1 -10 inclusive of inclusive of two index
f ingers is deduct ed into s ymbol capital letter I f or inner
while 11 or more O for outer.
3. A ridge count of 1 -13 inclusive of two ring f ingers is
deduct ed into capital symbol I f or inner and O f or outer.
Ridge tracing- It is the method of tracking or trailing the ridge
commencing f r om the lef t delta, with the number of ridges intervening
bet ween the right delta are accounted for and compared the table f or
corresponding symbol, capital letter I - M- O.
@ Tables f or symbols of whor l as a result of ridge tracing
1. W hen the ridge bein g traced (f rom the lef t to the right delta)
goes inside or in f ront of the right delta, and there are 3 or m ore
inter vening ridges, the tracing is known as inner and
represent ed by capital letter symbol I.
2. W hen the r idge being traced goes either or inside to the r ight
delta and t here ar e 2 or less ridges intervening the tracing is
known as meet ing and represented by the capital letter symbol
M.
3. W hen the ridge being traced goes outside to the right delta and
there are 3 or more inter vening ridges the tracing is known as
outer and represented by the capital letter symbol O.
Note: Arches are represented by a minus sign ( -)
d.The Major classif ication - are cr eated by counting and by tracing
ridges of the lef t and right thumb respectively. These divisions are t o
be used f or the purpose of subdividing large collections of prints.
In a large collect ion of prints wher e bot h thumbs are loop they are
divided into nine major divisions by counting the ridges of the thumb.
The ridge counts of the lef t thumb are represe nted in the denominator
by the symbol S, M, and L, which are arr ived at as f ollows:
Major di vi sion of loops
1. Ridge counts 1 to 11; inclusive are S (small), 12 to 16 inclusive, by
M (med), and 17 or over, L ( large).
2.The ridge counts of the right thum b are represented in the numerator
by the same symbols, M and L. The count in this instance f or the
small, medium and large is the sam e as just explained f or the
denom inator when an S or M appear s as denom inator.
3.W hen there are 17 ridges or more making a “Large” (L) in
denom inator the combinat ions changes in the numerator thus, the
combinations changes in t he numerator, thus: 1 to 17 inclusive S, 18
to 22 inclusive M, and 23 or more L.
Lef t Thumb Denom inator
Right Thumb Numer ator
1 to 11 inclusive S ( small)
1 to 11 inclusive S ( small)
12 to 16 inclusive M (medium)
17 or more ridges L (large)
12-16 Inclusive M (medium)
1-11 inclusive S (sm all)
12-16 Inclusive M (medium)
17 or more ridges L (large)
17 or more ridges L ( large)
1-17 inclusive S (sm all)
18 to 22 inclusive M (medium)
23 or more ridges L (large)
The f ollowing symbols are used t o illustr ate the sequences of the nine
combinations in this division.
S M L
------------S S S
S
M L
------------M M M
S
M L
------------L L L
Major di vi sion of w horls
In a large collect ion of prints when both thumbs are whor ls they are
divided into nine major divisions by t he result of ridges tracing in ner
(1), Meet ( M) and Outer (O) of both thumbs. The lef t thumb represent s
the denominator and the right thumbs the numerator.
The f ollowing symbols are used t o illustr ate the sequences of the nine
combinations in this division.
I M O
------------I I I
T M D
------------M M M
I M O
-----------O O O
e. Key Cl assificati on - is the r idge count of the f irst loop is a set of
prints beginning wit h the right thumb, but not includ ing either of the
litt le f ingers.
-
If there is no such loop, the key is the r esult of the ridge
count of the f irst whorl being treated as an ulnar loop.
-
W hen arches appear in all f ingers, the symbol of the key
classif icat ion is just a minus sign ( -)
-
The result of the ridge count of the key classif icat ion be
exhibited or placed at the extr eme lef t of the classif ication
f ormula in line with the numerator
f. Final classificati on - this is the r idge count of the loop in the little
f inger of the right hand, p laced in the numerator line
-
If there is no loop in the right little f inger, then the r idge
count of the one appear ing in the lef t little f inger/s used,
in which case it is placed in the denom inator line.
-
If no loop appear in either little f inger, the res ult of the
ridge count the whorl is being treated f or the f inal
classif icat ion
-
W hen arches appear in both little f inger the absence of a
loop or whor l or either in the right and lef t little f inger the
last loop is being used as a f inal classif ication, exc ept the
loop that is being used in the key classif ication.
-
Arches are r epresented
classif icat ion line.
by a minus
sign ( -)
in t he
Classification of scarred patterns (amputated, missing at birth
fingers)
a. Always indicat e t he amputated or missing at b birth f ingers to the
f ingerprint record cards.
b. If one is absent carry the symbol or counting by the counterpart, or
opposite f ingers, which is present.
C. If two amputated f ingers are opposit e each other, both are given
classif icat ion of whorls with M f or meeting.
d. if all f ingers were missing or amputated the classif ication will be;
N=
D=
M
M
32
32
W
W
MMM
MMM
e. If both hands are amputated or missing at birth the classif ication
will be.
Suspect fingerprint sample and data base making
Method/ essential of the f ingerprint sampling
Points of he f ingerprint sampling are as follows;
1. W ashing the hands bef ore f ingerprint sam pling
2. Relax
3.
4.
5.
6.
7.
8.
9.
Position
Area to be covered on the f ingerprint collection
Rolling dir ection of the rolling method
Spreading of ink
Thickness of the ink
Speed in rolling the fingers
Check up af ter f ingerprint recor ding
Search, preservation and collection of fingerprint evi dence
Fingerpr ints are ver y fragile and may be destroyed by
contamination or improper handling
The methods of searching, preservation and collect ion usually
aff ects both the qualit y and quantit y of latent f ingerprints.
The primar y concerns are preventing the addition of f ingerprints
to the evidence and prevent ing the destr uction of ones that are
already presen t.
So the f irst step to be undertaken in a case involving that
evidence is to exclude those unaut horized person and to prot ect
the scene.
SEARCHING - The search should begin with the area surrounding
the actual scene. The next logical places to search ar ea point s of
possible exit and ent ry.
PRESERVATION- when a latent pr int is located, the f irst thing to do
is to photograph the actual crime scene. A data car d should be
prepared and it should contain the case number, date, locat ion,
name of off icer who di scovered the pr int and the name of the
photographer. Next is to sketch the objects on which the latent
prints was f ound and indicate the exact location of the print.
LATENT I MPRESSIO NS
Each ridge of the f inger, palms and soles bears a r ow of sweat
ports, which in the aver age person const antly exude perspiration. Also
the ridge of the f ingers and palms are in intermittent contact with other
parts of the body, such as the hair and f ace, and with var ious objects,
which may leave a f ilm of grease or moisture on t he r idges. In
touching an object, the f ilm of moist ure and/ or grease may be
transf erred to the objects, thus leaving an outline of the ridge of the
f ingers or palm there on. This print is called a latent impression the
word “latent” meaning hidden, t hat is, the print many tim es is not
readily visible.
Latent impr essions, regardless of the area of the ridges present,
are of the greatest importance to t he crim inal invest igator as
identif icat ion of them may solve the cr ime and result in successf ul
prosecut ion of the subject. Consequently, ever y eff ort should be made
to preser ve and identif y them.
Visible pr ints in mediums such as blood, grease, dirt, or dust are
equally important to the investigator but strictly speaking, are not
latent impressions.
A search of the crime scene should be conducted in a logical
manner. Points of entry and exit should be exam ined, along wit
surf ace or objects disturbed or likely t ouched dur ing the commission
of the crime. The examiner should wear a pair of light cloth glove s and
handle an object only in so f ar as is necessar y and then only by edges
or surf ace, which ar e not receptive to latent impressions. A record of
the exact locat ion of a print on an objects and of the objects itself
should be made, since these f acts may be of the utmost importance in
any trial resulting f rom the invest igation. NO one should handle and
objects other than the examiner him self .
Portable articles r emoved should be labeled or marked so that
they may readily identif y thereaf ter.
The beam of a f lashlight played over the surf ace of an objects
will f requently show the location of latent impression, alt hough this is
not an inf allible test their presence.
Evidence should be exam ined as soon as possible af ter its
discover y. Following the locat ion of any latent prints scene of a crime,
the pr ints of all persons whose presence at the place under inspect ion
has been f or legitimate purposes must be excluded f rom f urther
attention. It is advisable, theref ore, during the initial stag es of an
investigation where latent pr ints are f ound, to secure the inked pr ints
of all members of the household, the employees, and any police or
other of f icial who have touched the objects on which the latent
impressions were f ound. Inked prints taken f or this purpose are
ref erred to as elim ination prints.
Due to the f ragment nature of most latent pr ints it is not
possible to derive a classif icat ion which makes a f ile search
practicable, a latent impression may be identif ied, however by
comparison with the prints of a partic ular suspects.
Inked f ingerprints taken f or comparison wit h the latent
impressions should be illegibly and as complete as possible including
the areas not essential to classif icat ion, since identif icat ion are of ten
made wit h these ar eas. Inked palm prints taken should likewise be
complete and clear and should include im pressions of the f inger joints.
Persons not exper ienced in latent comparisons should not attempt to
evaluate latent f ragment, since the area necessar y f or identif ication
may be extremely com pared to tat of an aver age inked f ingerprint.
Articles are which are to be transport ed by mail or expr ess
should be so packed that the surf ace bearing latent impr essions are
not in contact with other surf aces. This may be accomplished by
mounting the art i cles on a piece of a f iberboard or plywood. The board
should then be secured in a box so t hat the objects will not touch or
be taken against the side in transit. The package should be plainly
marked “Evidence”, t o prevent inadvertent handling on opining. C otton
or cloth surf ace never be placed in direct contact with any surf ace
bear ing latent pr ints.
Any number of paper or cardboard specimens may be placed in
a single protect ive wrapper, since contact with other surf ace does not
harm latent on such objects . Lif ts, negatives and photographs ar e
readily enclosed wit h letters.
An explanator y letter should accompany all evidence. If it is
necessar y to pack the evidence separately, a copy of the letter should
be placed in ever y package so tat the recipient will know immediatel y
the import of the contents. All items of evidence should be marked and
descr ibe exactly in the accompanying letter so that will not be
conf used with packing material of a similar nature, and to provide a
check on what the package should c ontain.
In addition, the lett er should include f or the recor d purposes
brief out line of the crime, i.e., date and place of occurrence, and
names of victims and subjects. If suspects are named f or comparison,
suff icient descr ipt ive data should be set out t o permit locat ion of their
f ingerprint recor ds. This inf ormation, in pref erential or der, comprises
individual’s complete name, aliases FBI number, date or prior arrest or
f ingerprinting, f ingerprint ident if ication, date and place of birth, and
physical des cription.
Evidence is pref erable f orwar ded by registered mail of railway
express, as these m eans provide recor ds of dispatch and receipt.
Elimination or suspect f ingerprints are best enclosed wit h evidence
itself , with notat ion as to the type of prints f o rwarded.
POW DERING ANF LI FTING LATENT IMPRESSION
The sole purpose in “developing a latent impression is to m ake
it visible so that it may be pr eser ved and compared various powders
and chemicals are used f or this purpose. W hen a latent prints is
plainly visible, it should be photographed bef ore any ef f ort is made to
develop it.
No attempt should be made to brush or apply powder t o pr int s in
just, obviously greasy or bloody pr ints, as this will almost surely
destroy them. Objects, which have been wet or i mmersed in water,
may still bear identif iable latent impressions. Bef ore any examinat ion
is attempted however, the objects must be dried.
Powder brushed lightly over a latent -bear ing surf ace will cling to
grease or moisture in the ridges of a latent print s, making it visible
against the background. Obviously, a powder should be used which
will contrast with t he color of the surf ace. Photographic contrasts
should also be considered.
A gray powder and black powder are adequate f or latent print
works. Many f ingerprint powders of var ious colors and com positions
are available f rom f ingerprint supply houses but none are superior to
the gray and black.
A ver y small amount of powder is placed on the brush f or
application to the surf ace. Once the contour of a prin t is visible, the
brush strokes should conf orm to the direction of the ridges. All excess
powder should be brushed f rom bet ween the r idges. Too much powder
and too litt le brushing are the chief f aults of beginners.
Gray powder is used on dark -colored surf aces. It is also used on
mirrors and metal surf ace which have been published to mirror like
f inish, sense these surf aces will phot ograph with the f ingerprint
camera. Black powder should be applied to white or light -color ed
surf aces.
Alum inum powder aff ord s the same contrast as the gray. Gold
and red br onze powders, although of a glittering appear ance, will
photograph dark and should consequently be used on light -colored
surf aces. Dragons’ blood powder is a photographically neutr al powder
and may be dusted on either a light or dark surf ace.
On clear transparent glass, either gray or black powder may be
used, it being necessar y only to use a contrasting black or white
background when photographing.
Prints should be lif ted af ter phot ographing both r ubber and
transparent tapes ar e available f or this purpose. Rubber lif ting tape id
procurable in black or whit e 4” x 9” sheets with the adhesive surf ace
protects with a celluloid cover. A black powder pr int should obviously
be lif ted on white tape and gray powder pr int on black tape.
Gold bronze and red bronze powders should be lif ted on white
tape, alum inum on block. Dragon’s blood is lif ted on either black or
white.
Af ter cutting a piece of tape suff iciently large to cover the entire
latent pr int, the celluloid c over ing is removed and the adhesive side
supplied to the latent. The tape should be pressed evenly and f irmly to
the surf ace, taking care not to sif t is position. It is t hen peeled gently
f rom the surf ace and the piece of celluloid placed over the print to
protect it. The operator should handle the lif t in such a manner that he
will leave no prints t o his own on the adhesive surf ace. A small paper
identif icat ion tag bearing the init ials of the operator, date an objects
f rom lif ted should be placed under one corner of the celluloid, or this
inf ormation may be wr itten on the black of the lif t itself if it can belong
in a permanent legible manner.
If an excessive am ount of powder adheres to the latent print,
more legible pr int may sometimes be obt ained by lif t ing a second time
(on a new piece of tape, of course).
It should be noted that a print lif ted on rubber tape is in a
reverse position. Consequent ly, in pr eparing a photograph of a pr int of
such a lif t, it will be necessar y to pr int t he negative f rom the r everse
side in order f or the pr int to appear in its correct position f or
comparison. Preparation of such photographs should not be attempted
be persons of inadequate knowledge an experience.
Transparent tape wit h a durable adhesive surf ace is available in
1” to 2” widt hs f or f ingerprint work. The common var iet y of transpar ent
tape is not suitable due t o the deterioration (dr ying) of the adhesive
surf ace. The print on a piece of transparent tape is in corr ect position.
Transparent lif ts should be af f ixed to a smooth gain less, opaque
background of a black or white color cont rasting with the powder used.
Ever y ef f ort should be made t o avoid air bubbles under such
lif ts. In no instance should a transparent lif t ever be f olded on itself or
struck. To another pi ece of such tape as a backing. Since it is
generally not possible to determine the correct posit ion of such a
print.
Groups of latent impressions, such as those of adjacent f ingers
and palms which appear to have been m ade simultaneously, shroud be
lif ted as units, that is, on single piece of tape, as this may f acilitate
the task of making comparisons.
PREP AR ATION OF FINGERTPRINTS CH ARTS FOR COURT
TESTIMONY
In testif ying to f ingerprint ident if icat ion, the expert of ten
prepares charts to visually aid the c ourt and jur y in understanding the
nature of his testimony. Many t imes it is undoubtedly diff icult the
layman to perceive, f rom a vocal explanation alone, the f ull import of
an expert’s testimony, due to its technical nature; consequently, some
graphic representat ion of the f acts presented is amply justif ied and
rewarded. The preparation of the charts is ultimately the sole
responsibilit y of the expert using them. As a matter of interest to law
enf orcement personnel engaged in f ingerprint work, a br ief
explanat ion of such charts f ollows, along with suggestions
remarks based on long experience in these matters.
and
To do the work conveniently, it will be necessar y to have
available, in addition to the ordinar y photographic developing and
print ing materials, a projection enlarger which will enlarge pref erably
to at least ten diameters. In the projection method of enlargement, the
image is pr inted direct ly f rom the original negative, and the
preparat ion of an enlarged negative is unnecessar y.
Aside f rom the ph ot ographic equipment, the needed materials
are:
A roll of scotch photographic tape 1 inch wide to
areas of the f ingerprints on the negative to be used;
cardboard approxim ately 1/32 inch thick on which t o
prepared charts a tube of rubber cem ent and a bottle of
ink, other than black or white.
out line the
some stiff
mount the
translucent
A light-box on which to view the negative whole blocking, and a
letter ing set to draw the lines and numbers unif ormly on the charts,
while not absolutely essent ial, are help f ul conveniences. A light -box is
basically a f rosted pane of glass wit a light beneath it to produce sof t,
even, none glaring illum inat ion. If no light -box is available, a clear
window may be ut ilized in “blocking” the negatives.
If the experts f ind it ne cessar y to have an outside source
prepare is photographs, he should ret ain personal custody of the
evidence dur ing the operat ion.
The original latent print and inked pr int with which it is ident ical
can be photographed 25 t imes the actual size. This proce dure
eliminates guesswork in enlarging both the same degree. W hatever
areas of the t wo pr ints are deemed requisite to illustrat e the method of
identif icat ion are then out lined ( blocked) on negat ive wit h the masking
tape, so the only those areas will show i n the subsequent
enlargements. Generally, if the legible ar ea of the latent print is small,
it is well to show the complete print. If the area is large, however, as
in a palm pr int, an area which will not make the cart too bulky or
unwieldy may be selected .
On blocking, the neg ative is af f ixed to the window pane or light box by means of strips of photographic tape across t he cor ners, wit
the side t o be blocked up. The pr event constant shif ting of the
negative while it is being prepared. The latent print sh ould be blocked
f irst. Corners of the blocked areas should be square. Cares should be
exercised to have as near ly as possible the same ridge f ormation
shown and the ridge f ormation in the same upr ight or hor izontal
positions. This may be f acilit ated by f ix ing a negative, bear ing ruled
squares bet ween the negative being blocked and the glass to which it
is attached.
If the latent pr int was developed or phot ographed as a light print
on a dark background, a reverse -color negative should be prepared
and blocked in order that both prints m ay appear as black ridges on
light. This is done by placing the or iginal negative adjacent t o a new
sheet of f ilm and exposing it. The resultant negative cont ains the
same image as the original except tat the color of the image has been
reversed.
If the negative is a photograph of an upper lif t, the print appears
reverse posit ion; tat is, as a mirror image, and the negative will
accordingly have to be blocked f rom the dull or emulsion side in order
f or it to appear in a positio n comparable to that of the inked prints.
Failur e to present t he pr ints in quest ion in the same color and
position may conf use the obser ver and nullif y the pur pose f or which
the chart is made.
The degree of enlar gement is not import ant in itself , so long as
the ridges of the latent print are readily dist inguishable by the eye.
Ten diameters have been f ound adequate, although any enlargement
f rom 5 to 30 will ser ve. It should be remembered however, that small
enlargements are diff icult to see a f ew feet awa y and tat background.
A white border of at least 1/1/2 inches or a width equal to one -third
the enlarged area should be lef t f rom carting purposes.
Any chart prepared must be technically correct; tat is, t he
corresponding ridge character ist ics in the two prints must be similarl y
numbered and indicated.
Several ways of pointing out the sim ilar ridge f ormations have
been obser ved but t he one which appears soundest is also simplest
and consists or merely marking the character istics wit h lines and
numbers.
All the r idge characteristics in t he print s need not be charted.
Twelve have t he r idge characterist ics are ample to illustrate f or
identif icat ion, but it is neither claimed nor implied that this number is
required.
All f ingerpr int identif ications are made by obser ving that two
impressions have the r idge character istics of similar shapes which
occupy the same relative positions in the patterns.
Method involving super imposition of the prints are not
recommended because such a procedure is possible only in a ver y f ew
instances, due to t he distortion of ridges in most prints through
pressure and t wisting. Such a procedur e is not necessar ily a test of
identif y.
Likewise,
presenting
charts
with
the
shapes
of
the
character ist ics drawn in the margin is not recomme nded. I ndividual
ridge character ist ics may var y slightly in actual shape or physical
position due to t wisting, pressure, incomplete inking condition of latent
print when developed, powder adhering to background, etc.
Identif icat ions are based on a number o f characterist ics viewed in a
unit relat ionship and not on the micr oscopic -appearance of single
character ist ic.
Since t he enlarged -photograph appear in black and white, an ink
other than black or white should be used to line the chart. Such an ink
should be pr ef erably translucent so that it will be possible to see the
ridges which it reverses. A translucent carmine drawing ink serves
well. In placing the lines the chart should be arranged so that they do
not cross or touch.
The chart will present a cleare r, hear er and mor e pleasing
appearance if it is numbered clock wise and the numbers are evenly
spaced. It is necessary however, to place the numbers evenly around
the photograph.
Ordinar ily, the numbers are placed on three sides and the t ype
of print (latent or ink) noted at the bottom. In any case, the manner of
number ing should be subser vient to an explanat ion of the
character ist ics in an orderly sequence; and, if the situation warrants it,
all of the points may be illustrated on a single side of the phot ograph.
A single line should be drawn f rom each char acteristic t o a
numbered point on t he march. Car e should be taken to draw t he line
exactly to the char acterist ics point, not short of it, beyond it or
obscur ing it. Erasur es should be avoided. If the ink runs or blots, it is
sometimes possible to remove it with a cloth in denat ured alcohol,
without damaging the photograph.
If the enlargement is great, that is 25 or 30 diameters, it might
be well to draw a small circle around each charact erist ic and then
draw the line f rom a circle to the number, since the r idge will be much
thicker than the illustrating line. All line and numbers should be
checked f or absolute accuracy. The expert should also study the
enlargements f or apparent discrepancies in the prints , which he might
be called upon to explain.
The chartered enlargements are readily mounted on stiff
cardboard wit h rubber cement, which maybe purchased in sm all tubes.
Af ter cementing the photograph to the cardboar d, it should be placed
under a heavy f lat object which will cover the entire surf ace to prevent
warping and wr inkling. After drying, trim the t wo enlargements to the
same square size with heavy scissor, a pen knif e or scalped, and
f asten them together, book f ashion. Of course, if charts are large , 0 to
36 inches square, mounting is unnecessar y and they will have to be
supported in the courtroom with thumbtacks or metal rings.
Some courts do not permit number ing or lining of the
photographs and the enlargements alone in these cases will have to
suff ice. If there is some question about admissibilit y of the charted
enlargements, it is well to prepare an ext ra -uncharted set.
DEFI NITION OF TERMS
1. Bif urcation – is the dividing of ridge into two or more
branches.
2. Enclosur e, Eye or eyelet – is t he splitting of a ridge into
two but meet at a certain point to continue as a single
ridge.
3. Divergence – is the spreading apart of two r idges which
have been parallel or nearly parallel.
4. Ending ridge – is a ridge that terminates.
5. Dot ridge – is a ridge that resemble a period.
6. Type lines – t wo innermost ridges which start parallel or
near ly parallel diver ge, and surround the pattern area.
7. Pattern Ar ea – is that part of a loop and whor l in which
appears the cores, deltas and ridges.
8. Delta – is that point on a r idge or in f ront of the near the
centers of the diver gence of the t ype lines. It may be a
bif urcation, an abrupt ending ridge, a dot , a short ridge, a
meeting of two r idg es or a point on t he f irst recurring
ridge located near est the cent er and in f ront of the
divergence of the type lines.
9. Core – is the approximate center of the patterns area.
10 Ridges- Little lines f ound at the f inger/palm of the hand
and sole of the f oot.
11. Focal point - it is within the pattern area of a loop and
whor l, whic h are enclosed and called delt a and cor e.
12. Frict ion skin - the epidermal hair less skin f ound on the
lower port ion of the hands and f eet covered wit h minut e
ridges and wit hout pigment or coloring matter.
13. Furrows- The canal or depression in bet ween r idges.