Review Flash Cards
QUESTION
ANSWER
QUESTION
How can you determine the direction glass
was broken by an object?
Radial fractures show up on the surface
opposite to the one where the fracturing blow
or pressure was applied.
What are the two things on a finger that are
deposited on a surface in order to produce a
latent print?
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Oil
Perspiration
What is Locard’s Exchange Principle and how
is this principle important to forensic
science?
Locard’s Exchange Principle states that
wherever a person goes a contact will be
made, leaving a transfer of materials between
person and area. The principle is important
because this is the way that evidence is left at
a crime scene or taken from the scene on a
criminal.
Three R Rule: Radial cracks form Right angles
on the Reverse side of the force.
What are two ways criminals have tried to
hide their fingerprints?
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Cutting off.
Burning off with acid.
What are the three main patterns and their
sub groups?
1)
Explain how glass cracks. In your answer,
include radial and concentric fractures.
Glass cracks because its’ elasticity is broken
due to applied force. Radial cracks form first
and are straight cracks from the center of the
applied force. Concentric cracks then form
circles around the center of the applied force.
What is the difference between a radial and
an ulnar loop?
Given two glass fractures located side-byside, explain how you can determine which
fracture occurred first
The radial fractures of a new crack will
terminate when they encounter another crack
that is already in the glass.
Define Latent print, Visible print and Plastic
print
Explain how you can determine the
difference between the entry and exit points
of a piece of glass that has been hit by a
projectile.
ANSWER
Arches:
a.
Regular
b. Tented
2) Loops
a.
Radial
b. Ulnar
3) Whorls
a.
Central pocket
b. Plain
c.
Double Loop
d. Accidental
Radial Loops – enter the core from the side of
the hand where the ulna is located (pinky), and
exit on the same side.
Ulnar Loops - enter the core from the side of the
hand where the radius is located (thumb), and
exit on the same side.
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A hit-and-run scene would have what type of
physical evidence?
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Paint Chips
Hair and Fiber
Glass
Possibly Some Biological tissues
Impressions
Name the techniques used to recover latent
prints on hard, non-porous surfaces. List
some examples of hard, non-porous surfaces.
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Surfaces:
Visible prints—can be seen with the
naked eye.
Latent prints—cannot be seen with
the naked eye.
Plastic prints—fingerprints left in a
waxy surface.
Iodine Fuming
Cyanoacrylate (super glue)
Dusting
Glass, Tile, Plastic
1. A fingerprint is an individual characteristic;
no 2 fingers possess identical ridge
characteristics.
2. A fingerprint will remain unchanged during
an individual's lifetime.
3. Fingerprints have general ridge patterns
that permit them to be systematically
classified.
The process of permanently preserving a
fingerprint from a crime scene.
Name the techniques used to recover latent
prints on soft, porous surfaces. List some
examples of soft, porous surfaces.
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Iodine Fuming
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Ninhydrin Fuming
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Silver Nitrate Fuming
Surfaces: Paper, Drywall
Have any two people been found to have the
same identical fingerprints?
No
When are fingerprints formed?
In the fetal stage of development.
Fingerprints reduce slippage and increase grasp.
What are minutiae points and how are they
important to the individuality of
fingerprints?
Minutiae points are microscopic
characteristics of ridges in fingerprints. Even
though people can have the same category of
prints, the minutiae points make each
individual print unique.
Besides identification, why is having the
friction ridges that make your fingerprints
important?
What is the most common type of fingerprint
pattern? The rarest type of pattern?
What is AFIS?
Automated Fingerprint Identification System.
It is a computerized system that stores
fingerprints of known offenders and can be
searched to find new suspects.
What happens when an antigen and the
same antibody are brought together?
They agglutinate (stick together) – this causes
clumping or clotting in the blood.
What substance, used to recover latent
fingerprints gives a white print after
processing?
Superglue fuming - also called cyanoacrylate
fuming.
Explain the test that would be used to
determine blood type.
Blood is mixed with the antibodies for types A
and B as well as rH. If the blood agglutinates, it
has tested positive for that type.
What substance, used to recover latent
fingerprints, gives a purple print after
processing?
Ninhydrin
What do you look for to determine if the
blood sample is from a male or female?
The Y chromosome
Define delta.
A small “up-side-down” V shape that appears
within most fingerprint patterns.
Who was the scientist that won a Nobel Prize
for his work with blood typing?
Karl Landsteiner
Define minutiae.
Within the pattern of ridges and valleys, the
minutiae points are points where the ridge
structure changes.
What two parts of the blood have the most
forensic information (aside from DNA)?
The red blood cells (erythrocytes)—contain
antigens and the serum—contains antibodies.
What are antibodies and where are they
found?
Antibodies are cells that fight off infection. They
are found in the serum (or plasma).
State the three principles of fingerprinting.
What is “lifting” a print.
What is the correct % distribution of loops,
arches, and whorls found in the general
population?
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60% of people have loops,
35% have whorls,
5% have arches
Most common = loops
Most rare = arches
What causes skin to form fingerprints?
Fingerprints are which type of evidence?
Define plastic fingerprints and know how
they can be collected and identified.
Iodine fumed fingerprints on paper appear
what color?
What is the name of the process that makes
the invisible blood visible?
List the four types of blood along with the
antigens and antibodies that would be found
together.
What does a blood stain that has impacted a
site at LESS than 90 degrees look like?
What shape does a blood stain that has
impacted a site at a 90 angle have?
Below the top layer of the skin, the epidermis,
is the dermis. At the top of the dermis lies
the papillary layer which connects with the
deepest layer of the epidermis. The papillary
layer supplies blood and nutrients to this area
with lots of dermal papillae which form waves
all along this layer. These waves form the
ridges and valleys to form fingerprints which
show on the epidermis.
Physical Evidence
What is a luminol test? What would a
positive reaction look like?
The luminol test detects whether or not blood is
present. A positive reaction would be glowing or
illumination of the stain.
What is the Kastle-Meyer Color Test? What
would a positive reaction look like?
Plastic prints—fingerprints left in a waxy/soft
pliable surface.
Collect by casting.
Redish-Brown
What is a Hemastix test? What would a
positive reaction look like?
Choices: (all are correct)
Kastle-Meyer Test
Luminol
Blue-Star
Fluorescein
LCV or Leuco Crystal Violet
Type A:
Type B:
Antigens = A
Antigens = B
Antibodies = B
Antibodies = A
Type O:
Type AB:
Antigens = None
Antigens = A & B
Antibodies = A & B Antibodies = None
More or less circular.
What material does the acid phosphatase
test look for?
The Kastle-Meyer color test detects whether or
not blood is present. A positive reaction would
be a pink color after adding phenolphthalein.
The Hemastix test detects whether or not blood
is present. A positive reaction would be green
color on the test.
The precipitin test is a test in which a precipitate
(clot) forms when human blood comes into
contact with human antiserum. It is a test for
human blood.
Semen
Oval or elliptical. The further from 90
degrees, the more elliptical it gets.
What is the precipitin test? What does it test
for?
Type AB blood contains what antigens and
antibodies?
Antigens = A and B
Antibodies = None
An individual who is type O has what type of
antigens and antibodies?
What is the string method is used to find at a
crime scene?
Antigens = None
Antibodies = A and B
To determine the point of origin of a spatter
pattern.
Which end of a bloodstain always point in
the direction of travel?
The tail end or the pointed end.
Backward spatter produced by a gunshot
wound can tell investigators___________.
The identity of the person involved, and
handedness of the suspect.
What is agglutination? When does it
happen?
Agglutination is the clumping of blood cells
due to an antibody-antigen reaction. It
happens when people get the wrong blood
type.
The removal of an object or surface that was
located between the origin of blood and the
target surface during the bloodstain
deposition leaves behind
___________________.
A Void
What is serology?
Serology is the study of antigen-antibody
reactions.
The skeletonized perimeter of a bloodstain
can be used to interpret_______________.
How old the stain is, how old it was when an
object was moved or when the spatter was
disturbed.
What is hemoglobin and why is it important?
Hemoglobin is a protein that carries oxygen
through the blood to the body.
Generally, bloodstain diameter ___________
as height increases.
Increases.
What is exsanguination?
Exsanguination is bleeding out due to the
breech of an artery or injury
What are RFLPs?
Restriction Fragment Length Polymorphisms – or
pieces of DNA of different length, created by
cutting them with a restriction enzyme.
What is asphyxiation?
Asphyxiation is the lack of oxygen to the brain.
What are restriction enzymes?
Enzymes that cut DNA at a specific site, called a
restriction sequence.
What is the difference between low velocity,
medium velocity, and high velocity blood
spatter? Include one cause of each in your
answer.
Low velocity:
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Speed = about 5 ft/second.
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3 mm or greater in diameter.
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Indicates blood is dripping.
Medium velocity:
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Speed = 6 – 25 ft/second.
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Between 1 - 3 mm in diameter.
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Indicates blunt trauma, sharp
trauma or cast-off.
High velocity:
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Speed = 100+ ft/second.
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Less than 1 mm in diameter.
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Indicating gunshot trauma, power
tools, an object striking with
extreme velocity (airplane prop) or
an explosion.
RFLP tests
What does “DNA” stand for?
Deoxyribonucleic acid
What are the base pairing rules? How do
they contribute to DNA’s ability to be
replicated?
What is CODIS and how does it help forensic
scientists?
Cytosine bonds with Guanine
Adenine bonds with Thymine
Describe the process of PCR and explain why
it is important to Forensic Science.
PCR allows forensic scientists to copy small
amounts of DNA that may be left at a crime
scene.
What was the first type of DNA testing
approved in the United States?
What is the difference between RFLPs and
STRs?
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What is the difference between flat gel
electrophoresis and capillary
electrophoresis?
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STR = Short Tandem Repeats –
looks for repeated sequences in
the DNA, then copies these
through PCR.
RFLP = Cuts the DNA at sites unique
in each individual, then organizes
them by length.
Flat gel – creates a 2D surface of
bands in multiple lanes (or
samples) of DNA.
Capillary – creates a 3D tube of
bands of one lane of DNA.
CODIS is a national database for offenders of
violent crime. It helps forensic scientists by
having a way to search for a DNA profile.
How should you package DNA evidence?
A container that is not air-tight. It prevents
evidence being contaminated by mold or
mildew.
How are RFLP’s used in Forensic Science?
Used to create a forensic or DNA profile to
identify individuals who left DNA at a crime
scene.
What is the process called in which DNA
makes a copy of itself?
Replication
What is the sugar component of DNA called?
Deoxyribose.
What is a nitrogenous base? Where are they
found in DNA?
A base that contains nitrogen. They are
adenine, thymine, cytosine, and guanine.
They are found on the nucleotide between the
backbones of the DNA.
What is the backbone of the DNA structure
composed of?
Deoxyribose Sugar and Phosphates
How does Cannabis differ chemically from
other narcotics?
Cannabis is not as addictive, and not as toxic.
What is forensic anthropology? What do
forensic anthropologists usually study?
Forensic anthropology is the study of bones and
skeletal remains, usually to make identification
of a victim of a crime.
A long bone such as the femur or the humerus.
How does manner of death differ from the
cause of death?
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Cause of Death – medical diagnosis
denoting disease or injury
(gunshot, stabbing, cancer)
Manner of Death – the intent of
the action that caused death
(Homicide, Suicide, Accident,
Natural Causes, Unknown).
What part of the body would a forensic
anthropologist most likely use to determine
height?
What are the five categories of manners of
death?
Homicide,
Suicide,
Accident,
Natural Causes,
Unknown
What part of the body would a forensic
anthropologist most likely use to determine
sex?
The pelvic bone or the skull.
What is the name of the person who
performs autopsies in cases where the cause
of death is questionable?
Medical Examiner
or
Coroner
What part of the body would a forensic
anthropologist most likely use to determine
race?
The skull.
The rate of cooling of a dead body can be
influenced by all of the following:
Environmental temperature,
Whether the body is wet,
Type of clothing,
Indoors or outdoors.
What is facial reconstruction and how could
it be useful to a forensic scientist?
Facial reconstruction is the building of clay as
tissue around a skull. It aides investigators in
finding victims of crimes.
What happens to the concentration of
potassium in the vitreous humor of the eye
after death?
According to forensic entomologists, which
"witness" (insect) is the first to arrive at the
crime scene?
They increase at a set rate.
What are defensive wounds and where
would they be likely found?
The Blow Fly
Forensic odontology refers to the study of
_______________.
Facial reconstruction is the building of clay as
tissue around a skull. It aides investigators in
finding victims of crimes.
Teeth.
Estimations of the postmortem interval
(PMI) using entomological evidence must
take into account __________.
How can investigators determine if a body
has been tampered with at a crime scene?
Environmental temperatures.
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Algor Mortis – Blood settling will
occur within a few minutes to a
few hours. If the blood has settled
in the body in such a way that it is
different from the position the
body was found in, it is an indicator
that the body has been moved.
Rigor Mortis – The stiffening of the
muscles will occur in the
environment that the body died in.
Any change in body position will
reveal that the body does not lay
correctly.
How many hair samples are required for a
suspects scalp to provide a good
representative sample?
What is the difference between a natural and
synthetic fiber? Which natural fiber is the
most common?
Approximately 50.
A natural fiber comes from either an animal or a
plant source. A synthetic fiber is man made.
The most common natural fiber is cotton.
Which phase of hair growth is characteristic
with having the best source of DNA?
Anagen
Sketch the three types of scale patterns
found on a hair shaft.
What characteristic needs to be looked at in
order to determine the sex of the person
that the hair sample belongs to?
What characteristics does a CSI observe first
when looking at hairs and fibers under a
microscope?
DNA
Which feature of hair is MOST important in
making a species identification?
The Medulla
Size and type of Medulla.
Pigment granules that impart hair with color
are found in the ____________ of the hair
shaft.
Cortex
What is a natural fiber?
A fiber produced by plants or animals – living
things.
Fibers made from plastics or other chemicals.
In what stage can a hair most readily be
removed from the scalp?
The rate of human hair growth per month
is_____________.
Telogen
What are three properties looked at when
analyzing fibers?
Length and shape of fiber, Color, Odor during
burning, Residue from burning,
Reaction during burning (does it melt or
incinerate?)
What type of evidence is hair without a
follicular tag?
Physical Evidence
Of the three layers of the hair shaft, which
layer is most resistant to chemical
decomposition?
The cuticle is the most resistant to chemical
decomposition.
Name the protein that hair is made up of.
Keratin
What is a manufactured (synthetic) fiber?
.22 cm / month
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Why is the cortex important in the hair
shaft?
The cortex contains the pigment that gives
hair its color.
What structures are necessary for calculating
the medullary index?
What part of the hair shaft contains scales?
The cuticle.
Name the cuticle pattern of human hair.
Imbricate
What are the three main classifications of
medullae?
The medulla is the central canal in the hair
shaft. The three main types of medulla are
continuous, discontinuous, and interrupted. A
4th category may be fragmented.
In which direction do hair cuticle scales
point?
Toward the tip of the hair.
Define fiber.
A thread or filament formed from a mineral
substance or textile.
Describe William Sheldon’s three body types
and tell which he believed to most likely be a
criminal.
Mesomorphs are most likely criminals.
Define yarn.
A thread or string spun from numerous fibers,
forming a pattern, such as a braid or a rope.
Define Modus Operandi.
The operating technique used by the offender.
The actions necessary to commit murder.
Define textiles.
A type of cloth or woven fabric.
Define Signature.
Who was Lombroso, and what was his
argument?
“Father of modern criminology”, gained much
attention in the field of criminology during the
end of the 19th Century. His classification of
criminals included categories such as born
criminals, criminaloids, and insane criminals,
as well as research on female offenders.
Define Staging.
The signature is often referred to as the “calling
card” of the offender. The person goes beyond
what is necessary to commit the crime, i.e. stab
a specific number of times.
Altering the crime scene to throw the
investigation, this may happen with organized
offenders.
When a forensic profile is being created
about an individual, what aspects about that
person’s crime must be assumed to remain
unchanged?
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Crime scene reflects the
personality of the offender.
M.O. remains similar.
Signature will remain the same.
Offender’s personality will not
change.
Contrast the two types of criminals
(according to the FBI method) – Organized
and Disorganized.
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Medulla width.
Shaft width
Whether or not the crime scene is left
ORGANIZED or DISORGANIZED is said
to provide information about the
offender’s criminal sophistication and
personality.
Organized crime scene reflects
offender who commits crime out of a
need for power. Motivation
associated with PSYCHOPATHY.
Disorganized crime scene reflects
offender who commits crime out of
passion, compulsion, frustration, or
anxiety. Motivation associated with
PSYCHOSIS.
PSYCHOPATHY:
Personality disorder made up of a particular
constellation of characteristics.
Lack of attachment, defect in affect, absence
of anxiety.
In touch with reality.
Severe Lack or Empathy.
PSYCHOSIS:
Clinical mental illness – Schizophrenia.
May meet legal definition of insanity.
Out of touch with reality.
The application of science and technology
to those criminal and civil laws that are
enforced by police agencies in a criminal
justice system.
What do the following stand for and what are
they used for (Hint: they are all databases)?
IAFIS
CODIS
NIBIN
PDQ
SICAR
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What are 4 reasons for the rapid increase in
the number of crime labs?
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Name and Describe the first procedure used
to distinguish one individual from another
individual.
What was the oldest laboratory in the US?
Anthropometery – measurement of specific
parts of the body as a means of identification
How do you obtain reference samples?
LAPD Crime Lab
What did each of these famous people (in the
field of forensics) do? Francis Henry Galton
Alphonse Bertillon
Karl Landsteiner
Edmond Locard
Sir Alec Jeffreys
What is an expert witness and how do they
differ from a lay witness?
An expert witness can give facts AND opinions
based upon their training and knowledge in a
field. A lay witness can only testify to those
things known as facts—NO opinions can be
given.
What are the basic metric units for mass,
volume, and length?
Compare psychosis to psychopathy.
What is the definition of forensic science?
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CODIS = Combined DNA Index System
IAFIS = International Automated
Fingerprint Identification System
NIBIN = National integrated Ballistics
Information Network
PDQ = Automotive Paint Data Query
SICAR = Shoeprint Image Capture and
Retrieval
Increase in crime rates;
Increase in drug-related arrests;
The advent of DNA testing;
Emphasis on scientific evidence by
Supreme Court rulings.
Collect samples of known substances from the
crime scene or from suspects with which to
compare unknown specimens.

Francis Henry Galton – devised the
methods for classifying fingerprints.
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Alphonse Bertillon – Devised a system
for identifying individuals by
measuring structures of the body.

Karl Landsteiner – Devised the test to
determine blood type.

Edmond Locard – Locard’s exchange
principle, two object cannot interact
at a crime scene without leaving
exchanging traces.

Sir Alec Jeffreys – Created DNA
fingerprinting.
Mass is the gram;
Volume is the liter;
Length is the meter