-That branch of chemistry which deals with the
application of chemical principles that arise in
connection with the administration of justice
-Concerned
with the proper collection,
preservation and transportation of evidence.
A.
-
The circulating tissue of the body
THREE COMPONENTS OF
1)
2)
3)
Erythrocytes, or red corpuscles
Leukocytes, or white corpuscles
Blood platelets
the constituent of blood responsible for the formation of
haemocromagen crystals
-The
fluid or liquid portion of the blood where the cells
are suspended
-The
most abundant protein in the blood
-The
soluble precursor of fibrin which forms blood clot
-Straw-colored
liquid squeezed out of clotted blood if
allowed to stand for some time
-The liquid that separates from blood when it coagulates
- means blood clumping
1) PRELIMINARY TEST
-determines whether stain is blood or
another substances
2) CONFIRMATORY TEST
-confirms the result of the preliminary test
-conclusively identifies substances as blood
3) PRECIPITIN TEST
-determines if blood is of human or animal
origin
-if human blood, there appears a white ring
the tube
4) BLOOD GROUPING TEST
-determines the blood group, if human
blood
1) BENZEDINE TEST
-if positive, the result is blue
2)
PHENOLPHTHALEIN TEST
-if positive, the result is pink
-when exposed to ammonia fumes, it gives off pink
3)
4)
GUAIACUM TEST- beautiful blue
LEUCOMALACHITE GREEN TEST-recommended by Edler1904
-blue-green/ Peacock Blue
5)
LUMINOL TEST
-if positive, haemcromagen crystals will be produced
-color of the crystals is salmon pink
-shape of the crystals is rhombic
Microscopic Test
1.
2.
3.
Human-reddish circular
Mammals- biconcave reddish
Avis Reptiles- oval
Acetonic-haemin/ wagenhaar test
- small dark, dichronoic acicular crystal-Aceteneo
haerain are seen
1)
2)
3)
4)
TYPE A
TYPE B
TYPE AB- rarest blood type
TYPE 0- the most common blood type
-
-
Stands for DEOXYRIBONUCLEIC ACID
Functionally, it is the hereditary material that
contains
the genetic information necessary
for the duplication of cells and for the
production of proteins
Chemically, it is an acid, containing deoxyribose
sugar and contains four bases:
a)
b)
c)
d)
-
-
A- adenine
T- thymine
C- cytosine
G- guanine
structurally, it is a double-helix composed of two
complimentary strands
All cells in the body have the same DNA
composition
-British
molecular biologist who first recognized DNA analysis
as having application to forensic science
1)
2)
3)
4)
-
It is sable- it can be isolated from material even after a
long period of time
DNA can be examined from wide variety of biological
resources
DNA can be replicated in the laboratory through the
process of POLYMERASE CHAIN REACTION (PRC)
DNA shows greater variability from one individual to next
Unity of heredity
Complex chemical units contained in the chromosomes
Carriers of heredity
-Microscopic
rod-shaped bodies bearing genes
which carries the traits for transmission
-Every normal individual has 46 pairs of
chromosomes
-A technique for replicating or copying a portion of
a DNA strands outside a living cell
-A
viscid, whitish fluid secreted by the male reproductive tract
consisting of spermatozoa suspended in secretion of accessory
glands
1.) SEMINAL FLUID
viscid, gelatinous and sticky
Has characteristic alkaline odor
Becomes more liquid in character when exposed to air
Slightly alkaline in reaction
2.) ORMED CELLULAR ELEMENTS:
-
a)
b)
c)
Spermatozoa or sperm cell
Epithelial cells
Crystals of choline and lecithin
1-5 to 3-5 cc.
- the normal quantity of seminal fluid in a single
ejaculation
400-500 million -the total number of spermatozoa contained in a
single ejaculation of a healthy young man
-A
condition where male have no spermatozoa at all their seminal
fluid
-A
condition where males have abnormally low sperm counts or
very few spermatozoa
1)
2)
3)
-
As fresh:
Vaginal contents
Rectal contents
As wet or dry condition
Hair
Skin around the genitals
As dry strains
Underclothing
Bed clothing
Microscopic Test
1. Test Spermatozoa (Fresh)
2. Test Spermatozoa (if dry specially to seminal stain
dirty- tail green & Red head if it is stained w/ Loff
ler’s Sol.
Dr. Glaister- Found spermatozoa after 46 hrs (death)
Aspermia-No spermatozoa
Ologospermia- few spermatozoa
Ovarisim- No sperm caused by VD \Testicular Damage
1)
2)
PHYSICAL EXAMINATION-alkaline odor,brown if dry
CHEMICAL EXAMINATION
a)
Florence Test- specific to human
-Dr. Flourence Lyons- needle look
like( dark brown crystal, rhombic)
b)
Barberio’s Test-restore semen evidence. Max
of 6 yrs (prostic Secreation)
c)
Acid Phosphates Test- Dr Sydney Keye (Separate
spermatozoa to seminal to fluid)
3) MICROSCOPIC EXAMINATION-Yellow tinted Rhombic
crystal, due to picric acid-(Salmon
to Flesh)
4) BIOLOGICAL EXAMINATION- det. Animal to human
-That
mixture of chemical of barious compositions
designed to propel the projectile by means of the
expansive force of gas when burned
-Also
BLACK POWDER
1)
The oldest of the propellants
Composition is the following:
Sodium nitrate =75%
Sulphur
= 10%
Charcoal
= 15%
-
2)
called propellant or powder charge
SMOKELESS POWDER-
The most powerful of propellants
1)
2)
-
3)
4)
-
SINGEING
The slight burning of clothing or the skin around the bullet hole
SMUDGING
The blackening of the area surrounding the bullet hole
TATTOOING
The individual specks of nitrates and nitrites around the bullet hole visible
to he naked eye
PRESENCE OF NITRATES
Can be determined when paraffin test is conducted
-Radiographic
Exam and Gunshot wounds
-Infrared Photograph- around the wound
-Reveals Smoking
1)
2)
3)
4)
0 to 2 inches (contact firing) – there is the presence of all the
characteristics patterns
2 to 6 inches – there is singeing, smudging, tattooing and presence
of nitrates
6 to 12 inches – there is smudging, tattooing and presence of
nitrates
12 to 36 inches – there is tattooing and presence of nitrates
-The
taking of the cast to extract the nitrates
embedded or implanted on the skin
-Must be done within seventy-two (72) hours or
three days
-Determines
the presence and distribution of
nitrates through the use of the diphenylamine
reagent; the chemical aspect of the test
-Minute
specks of blue in color will appear
when positive for nitrates-On hands, the nitrates appears greenish-blue
when dropped with diphenylamine reagent
1)
2)
3)
4)
5)
6)
Type and caliber of the ammunition- different types of ammunition
fired in the same weapons and from the same distance may give
different patterns
Length of the barrel of the gun- a weapon with a shorter barrel will
deposit residues over a larger are than a weapon with al longer
barrel even thought they are fired from the same distance and with
the same type of ammunition
Distance of the muzzle from the target- the closer the muzzle, the
more residues it will deposit
Humidity- power having lesser amount of moisture will burn more
rapidly and completely with in a given time, yielding greater amount
of residue
Wind velocity and direction- in high winds, the residue will be blown
in the direction of the wind yielding a scattered pattern
Direction of firing- when gun is fixed downward or vertically, all of the
residues will fall on the target, but when fired horizontally, some of
the residues are likely to fall short of the target
-Any
substances that may cause an explosion by its sudden
decomposition or combustion
-A material, either single substance or mixture of substances, which is
capable of producing an explosion by its own energy
-When exploded, it is almost always accompanied by heat and
formation of
gas
1)
-
2)
3)
-
PROPELLANT OF LOW EXPLOSIVES
Combustible material containing within themselves all oxygen
needed for their combustion which burn but do not explode and
function by producing gas which produces explosion
PRIMARY EXPLOSIVES OR INITIATORS
Explode or detonate when they are heated or subjected to shock
The material themselves explode but do not burn
HIGH EXPLOSIVES
Explode under influence of shock of the explosion of a primary
explosive
Examples are ammonium nitrate (AN), dynamite, trinitrotoluene
(TNT, the most widely used explosive), nitroglycerine
-An
appendage of the human body which appear all
over the body except on palms and soles
-A slender, tread-like growth of the skin
-In human hair, the medulla is interrupted and its
medullar index is less than 0.5
-In animal hair, the medulla is continuous and its
medullar index is more than 0.5
1)
2)
3)
-
Root
Portion embedded in the skin
Shaft
Portion above the surface of the skin
The most distinctive part
TIP
The distal end of an uncut hair shaft
CUTICLE
1)
-
The outermost covering if the hair
MEDULLA (0.05mm to Animal and 0.05 mm to Human)
2)
-
Center of the hair structure
CORTEX
3)
-
The intermediate and the thickness layer of the shaft
NATURAL
SYNTHETIC OR ARTIFICIAL
1)
2)
U. V Test
VEGETABLE
1)
-
Made of cellulose
ANIMAL
2)
-
Made of protein
3)
MINERAL
1)
ORGANIC
INORGANIC
2)
Veg.- Yellowish Green Color
Animals- Bluish Color
Natural Silk- Very Bright Blue
White than acetate in
daylight
Nitro Silk- Brilliant Light blueyellowish in daylight
Unbleached wool- Brilliant Blue
A simple preliminary examination
Determines whether fiber is mineral, animal or
vegetable
-
Determines the general group to which a fiber belongs
However it is not reliable for positive identification of
fiber
-
-
The most reliable and best means of identifying fiber
fiber (NaOH- cultivated silk dissolved
Lead/Alkaline-wool-brown to black
-The
process of reproducing physical evidence by plaster
molds
--Stereoscopic exam is best to see striation in the
impression, ridges, depression
-A faithful reproduction of an impression with the use of
casting materials
-Any
material which can be changed from a plastic or liquid
state to the solid condition
-Best casting material is PLASTER OF PARIS
-To hasten the setting time, table salt is added
-To retard the setting time, sugar or borax is added
-SHELLAC is sprayed on the impression to harden the sides
-The
process of extracting and working on metals by
application of chemical and physical knowledge
-Branch
of metallurgy that deals with the study of the
microstructure of metals and alloys
-Chemicals used in restoring tampered serial
numbers
-The
branch of geology which deals with the systematic
classification and identification of rocks, rocks-forming mineral and
soil
-Also includes study of dust, dirt, ceramics and other such materials
1)
2)
3)
1)
2)
3)
4)
PRIMARY MINERALS
CLAY MINERALS
ORGANIC MINERALS
DENSITY GRADIENT APPARATUS
X-RAY DIFFRACTION
SPECTOGRAPHIC ANALYSIS
THERMAL ANALYSIS
I. CHEMICAL ASPECTS OF DOCUMENT
EXAMINATION
DOCUMENT
An original or official written or printed paper furnishing information or
used as proof of something else.
PACKING, PRESERVATION AND TRANSPORTATION OF EVIDENCE/DOCUMENTS
1.Documents
should be handled, folded and marked as little as possible.
2.If folding is necessary to send to the laboratory, the fold should be made
along old lines. Place it in a Manila paper envelope or brown
envelope or it can be placed in a transparent plastic envelope.
3.On receipt the document should be placed between two sheets of plane
white paper in folder.
4.Documents should not be touched with pencil, pen or anything that could
possibly mark them.
THE EXAMINATION OF QUESTIONED DOCUMENTS
EXAMINATION AND COMPARISON OF PAPER
The essential materials in a document examination of any kind
are the paper and ink or pencil or writings. The examination of paper
maybe necessary if we want to know the age of the document, the
presence of alterations, erasures and other forms of forgery.
PROBLEMS ENCOUNTERED IN DOCUMENT EXAMINATION ANALYSIS OF
PAPER
1.
2.
3.
Whether two pieces of paper originated from the
same source.
Determine of probable age of paper.
Determination of the composition of paper.
COMPOSITION OF PAPER
Paper is made of three components namely:
1.
2.
3.
Fiber Composition
Sizing Material – to improve quality of paper
Loading Material – to add weight to the paper
EGYPTIAN PAPYRUS - one of the earliest substance used for writing. It
is form the name papyrus, that the word paper was derived.
FIBER COMPOSITION: practically all papers maybe classified form the
standpoint of their basic fiber composition into sets of fiber
mixtures namely:
a)
b)
c)
mechanical pulp-ground wood sulfite mixture.
Soda-sulfite mixture
Rag sulfite
SIZING MATERIAL – added to paper to improve its texture.
Examples of sizing materials are rosin, casein, gelatin, starch.
LOADING MATERIAL – added to paper to give weight. It partially
fills the pores between the fibers of the paper. Examples are
calcium sulfate and barium sulfate.
THE EXAMINATION OF PAPER
The four test for paper:
1.
2.
3.
4.
Preliminary Examination
Physical test causing no perceptible change
Physical test causing a perceptible change
Chemical Test
PRELIMINARY TEST FOR PAPER
I.
The test deals with the appearance of the document and the
following are observed:
a.
b.
c.
d.
folds and creases
odor
impressions caused by transmitted light
presence of discoloration and daylight and under ultraviolet light.
WATERMARKS – it is a distinctive mark or design placed in the paper
at the time of its manufacture by a roll usually a dandy roll.
WIREMARKS – marks produced on paper by the flexible wire soldered
to the surface of the dandy roll that carries the watermark.
PHYSICAL TEST CAUSING NO PERCEPTIBLE CHANGE
A test applied on paper without perceptibly changing or
altering the original appearance of the document.
a.
Measurement of length and width
b.
Measurement of thickness
c.
Measurement of weight/unit area
d.
Color of the paper
e.
Texture
f.
Gloss
g.
Opacity
h.
Microscopic Examination
OPACITY – the quality of paper that does not allow light to pass through
or which prevents dark objects from being seen through the paper.
PHYSICAL EXAMINATION CAUSING A PERCEPTIBLE CHANGE
This is done only if sufficient samples are available and if proper
authorization from the court is acquired this can be done.
a.
b.
c.
d.
bursting strength test or “POP” test
folding endurance test
accelerated aging test
absorption test
CHEMICAL TEST - This test determines the fiber composition, the
loading material and sizing material used in the paper.
FIBER COMPOSITION – examination is purely microscopic and it
determines the material used and nature of processing.
LOADING MATERIALS – is determined by burning and ashing a
portion of the paper and then the ash examined.
SIZING MATERIAL – gelatin is extracted by boiling the paper in
water and the solution treated with tannic acid; rosin is extracted
by heating the paper with 95% alcohol. The alcohol evaporated
and the residue treated with acetic anhydride and strong sulfuric
acid; starch is determined by addition of dilute iodine solution;
case in is determined by addition Millon’s reagent.
INK
Some of the most important questions that arise in the
analysis of inks are:
1.
2.
3.
4.
Whether the ink is the same or like or different inking
from ink on other parts of the same documents or
other document.
Whether two writings made with the same kind of ink
were made with the identical ink, or inks of different
qualities or in different conditions.
Whether an ink is as old as purports to be
Whether documents of different dates or a succession
of differently dated book entries show the natural
variations in ink writing or whether the conditions
point to one continuous writing at one time under
identical conditions.
TYPES OF INK
1.
2.
3.
4.
5.
6.
Gallotannic ink or iron-nutgall ink – the type of ink where age maybe determined.
Today the most frequently used ink for making entries in record books and for
business purposes. Gallotannic ink is made of a solution off iron salt and nutgall.
This
ink can penetrate into the interstices of the fiber and not merely on the surface,
thus making its removal more difficult to accomplish.
Logwood ink – made of saturated solution of logwood to which very small amount of
potassium dichromate is added. Hydrochloric acid is added to prevent formation of
precipitate. Phenol is added as preservative. This ink is inexpensive and does not
corrode steel pen. Will not wash off the paper even fresh, flows freely.
Nigrosine Ink or Aniline Ink – made of coal tar product called nigrosine dissolved in
water. It easily smudge, affected by moisture, maybe washed off from the paper
with little difficulty. It is best determined by spectrographic method.
Carbon ink or Chinese ink or India Ink – the oldest ink material known. Made of
carbon in the form of lampblack. Does not penetrate deeply into the fibers of the
paper so that it may easily be washed off. Not affected by the usual ink testing
reagents.
Colored writing ink – today, almost all colored inks are composed of synthetic aniline
dyestuffs dissolved in water. In certain colored inks ammonium vanadate is added to
render the writing more permanent.
Ball Point Pen ink – made of light fast dyes soluble in glycol type solvents as carbitol,
glycol or oleic acid. Paper Chromatography is the best way of determine this type of ink.
TEST FOR INK
1.
2.
3.
Physical Test
Chemical Test or Spot Test
Paper Chromatography Test
DISCUSSION OF TEST
1.
2.
3.
Physical Test – applied to determine the color and presence of
alterations, erasures, destruction of sizes with the use of
stereoscope, handlens or microscope.
Chemical Test – a simple test wherein different chemicals or
reagents are applied on the ink strokes and the chemical reactions
or characteristic color reactions or other changes in the ink is
observed. Reagents used: 5% HCI, 10% oxalic acid, tartaric acid, 2%
NaOH, 10% NaOC1, C12, H2O, KCNS, water.
Paper Chromatography – a reliable procedure that can be adopted
to identify and compare ballpoint pen ink.
DETERMINATION OF APPROXIMATE AGE OF DOCUMENT
Age of Ink – no definite procedure which can be given for this determination except
when the color is black, because on the observation that within a few hours, the
color of ink writings becomes darker because the dye contain therein is influenced
by the light of the room, oxygen of the air, acidity or alkalinity of the paper.
1.
There are several methods of determining the degree of
oxidation of the ink writing and apparently these methods
depend upon:
1.
Physical phenomena such a matching the color of the ink writing with the
standard colors of with itself over a period of time.
2.
Chemical reaction that may reveal some information concerning the length of
time the ink has been on the paper
2.
Age of paper
a.
b.
through watermarks
in certain case from the composition of paper
OTHER ASPECT OF DOCUMENT EXAMINATION
ILLEGIBLE WRITINGS – unnecessary writings that are not capable
of being read usually made on checks, birth certificate, passport and
transcript of record.
SOME ILLIGIBLE WRITINGS
1.
Erasure – means removal of writing from the paper. Can be made
chemically or mechanically.
2.
Obliteration – the obscuring of writing by superimposing ink,
pencil or other marking material.
3.
Sympathetic Ink or Invisible ink – substances used for invisible
writing.
4.
Indented Writing – term applied to the partially visible depression
appearing on a sheet of paper underneath the one that the visible
writing appears.
5.
Writings on Carbon Paper – used sheets of carbon paper can be
made readable.
6.
Contact Writing – black paper may contain traces of ink because
of previous contact with some writings.
the theory of Metwyeff
(Stretching)
Metwyeff-Russian Criminologist explain in diff. curves
-Super
cooled liquid which possesses high viscosity and rigidity
-non-crystalline inorganic substances
Silica
Soda(Na₂O)
Lime (CaO)
MgO
Al₂O₃/K₂O
-Base commercial glasses
-act as flex for sil
-give durability
- Impurity
-gives greater chem. Durability &
freedom from devitrification
-
The most important constituent of glass
-
Stress lines produced on a glass pane which are
perpendicular to the rear
Known also as primary fracture which resemble the spokes
of a wheel radiating outward from the point of impact
-
-
-
Stress lines which are on a glass pane perpendicular to the
front
Known also as secondary fracture having the appearance of
circles around the point of impact connecting one radiating
crack to the other and forming triangular pieces of glass
TYPES OF GLASS:

Soda-lime glass: Mostly
sand, sodium carbonate
and calcium oxide:
 Used
for
manufacturing
most window and
bottle glass
FLOAT GLASS
Flat glass typically
used for windows.
 Soda-lime glass
that has been
cooled on top of a
bath of molten tin.

BOROSILICATES

The common metal-oxides found
in soda-lime glass are sodium,
calcium, magnesium and
aluminum.

In addition, a wide variety of
special glasses can be made by
substituting in whole or in part
other metal oxides for the silica,
sodium and calcium oxides.

Automobile headlights, heatresistant glass such as Pyrex are
manufactured by adding Boron
oxide to the oxide mix

Lab glassware, thermometers,
cookware.
LEADED GLASS

Fine glassware and
decorative art glass, called
crystal or leaded glass
substitutes lead oxide for
calcium oxide (lime).

The addition of lead oxide
makes the glass denser. As
light passes through the
more-dense glass, the light
waves are bent, giving the
glass a sparkling effect.
TEMPERED GLASS

This glass is made stronger
than ordinary window glass
by introducing stress through
rapid heating and cooling of
the glass surfaces.

When tempered glass
breaks, it does not shatter
but rather fragments or
“dices” into small squares
with litter splintering.

Used for side and rear
windows of automobiles sold
in the United States.
LAMINATED GLASS

This glass derives its
strength by sandwiching
one layer of plastic between
two pieces of ordinary
window glass.

The windshields of all cars
manufactured in the United
States are constructed from
laminated glass.
BULLETPROOF GLASS




Bulletproof glass is a combination of two
or more types of glass, one hard and one
soft.
The softer layer makes the glass more
elastic so it can flex instead of shatter.
The index of refraction for both of the
glasses used in the bulletproof layers must
be almost the same to keep the glass
transparent and allow a clear view through
the glass.
Bulletproof glass varies in thickness from
three-quarter inch to three inches.
ANALYSIS / TEST FOR GLASS
1.
2.
3.
4.
5.
Spectrographic analysis/test
X-ray diffraction analysis/test
Physical properties examination
Ultraviolet light examination
Polish marks examination
DISCUSSION OF TEST
SPECTROGRAPHIC TEST – an instrumental method of analysis that determines
the presence of trace element. Shows the constituent elements of a glass. It will not
give sufficient information to establish the origin of the samples examined. A rapid
examination and an adequate method for glass analysis since it requires only a
small amount of sample.
X-RAY DIFFRACTION ANALYSIS – not as effective as the spectrographic analysis. Determines
the type of pattern of glass. The type of pattern depends upon the composition of
glass.
PHYSICAL PROPERTIES EXAMINATION – the most sensitive method of determining
differences of composition in glass samples and it depends upon the study of the
physical properties of glass. Properties like specific gravity or density, refractive index.
ULTRAVIOLET LIGHT EXAMINATION – determines the differences in the appearance of their
fluorescence thus indication of physical and chemical differences.
POLISH MARKS – optical glass and other fine glassware are usually polished. In the
polishing of glass fine marks are often left on the surface that can sometimes serve as
a basis of comparison.
GLASS AS EVIDENCE OF CRIME
In the field of Forensic Chemistry emphasis is placed on:
1.
2.
3.
Automobile glass in case of hit and run.
Broken windows caused by pressure, blow or bullet
in case of robbery.
Broken bottles, drinking glass or spectacles found
at the scene of assault or other crimes of violence.
THE PRINCIPLE OF 3Rs RULE FOR RADIAL CRACK
3RsRule – “Stress lines on a radial crack will be at right
angle to the rear side of the glass.”The front side is
referred to as the side that was struck.
THE PRINCIPLE OF RFC RULE FOR CONCENTRIC CRACK
RFC Rule – “Stress lines on a concentric crack will be at right
angle to the front side” that is the side from which the
blow came, rather than the rear sides
1)
2)
-
3)
4)
-
5)
-
SPECTOGRAPHIC TEST
An instrumental method of analysis which determines
the presence of trace elements
Shown the constituent elements of a glass
X-RAY DIFFRACTION TEST
Determines the type if pattern of glass
The type of pattern depends upon the composition of
glass
PHYSICAL PROPERTIES EXAMINATION
The most sensitive of determining differences of
composition in glass samples
ULTRAVIOLET LIGHT EXAMINATION
Determines the differences in the appearance of their
fluorescence which indicate physical and chemical
differences
POLISH MARK TEST
Polish marks serve as basis of comparison
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