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Forensic Science - 2023 > Exam #2 > Flashcards

Exam #2 Flashcards

1
Q

The pores of the sweat glands are located in the:

A

skin ridges

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2
Q

Prints that are not readily visible are commonly referred to as:

A

latent

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3
Q

To permanently alter the fingerprint and produce scars, one must damage the:

A

dermal papillae

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4
Q

The most common ridge pattern is the:

A

loop

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5
Q

The number of deltas found in an arch pattern is ________ the number of deltas found in a loop pattern.

A

less than

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6
Q

In the Primary Classification System, a finger is assigned numerical value if its pattern is a:

A

whorl

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7
Q

The fingerprint classification system used in most English speaking countries was devised by:

A

Henry

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8
Q

What did Henry do?

A

devised the fingerprint classification system that is used in most english speaking countries

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9
Q

What is AFIS

A

computerized fingerprint database

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10
Q

Prints impressed in a bar of soap are referred to as:

A

plastic

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11
Q

Will West was the man who:

A

had a virtual “double” with a similar name

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12
Q

Physical developer contains:

A

silver nitrate

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13
Q

Superglue fuming is NOT suitable for use on:

A

cardboard

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14
Q

Currently, which of the following, in conjunction with chemically induced fluorescence, is most often used to visualize latent prints?
Laser illumination
IR light
UV light
High-intensity light sources

A

high-intensity light sources

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15
Q

Dusting to visualize a latent print on finished leather and rough plastic is best done with a:

A

magna (magnetic) brush

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16
Q

After successfully visualizing a latent print on an object, an investigator should next:

A

take a 1:1 photograph of the print

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17
Q

Which of the following types of fingerprints are more likely to be found impressed in soft wax?
Hidden
Visible
Plastic
Latent

A

plastic

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18
Q

Under which circumstances have two people been found to have identical fingerprints?
Siamese twins
Fraternal twins
Identical twins
None to date

A

none to date

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19
Q

Protein residues are best developed into fingerprint impressions with:

A

ninhydrin

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20
Q

Which statement is true of a partial fingerprint?
-It must show at least a little of all ten fingers.
- Any print is sufficient for identification as long as there is enough to identify its basic pattern.
- At least 75% of the pattern must be present for identification.
- Any print can identify a criminal if it shows an adequate number of ridge characteristics.

A

any print can identify a criminal if it shows an adequate number of ridge characteristics

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21
Q

Which of the following is NOT a ridge characteristic of a fingerprint?
Island
Core
Enclosure
Bifurcation

A

core

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22
Q

A point-by-point comparison of a fingerprint’s ________ must be demonstrated in order to prove identity.

A

minutiae

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23
Q

Which step of the ACE-V process requires the examiner to identify any distortions associated with the friction ridges?
Analysis
Evaluation
Verification
Comparison

A

analysis

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24
Q

Fingerprints are formed:

A

during fetal development

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25
Q

The friction skin ridges:
Have no useful purpose other than identification.
Provide a firmer grip.
Resist slippage.
Both B and C

A

both b and c

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26
Q

The FBI has an internal unit called FACE. What does FACE stand for?

A

Facial Analysis, Comparison, and Evaluation

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27
Q

Which of the following pathways would represent an accurate portrayal depicting the collections steps in gathering biometric data?
-Biometric sensor Pre-processing Feature Extractor Template generator
-Stored templates Matcher Template generator Decision
-Decision Template generator Pre-processing Stored templates
-Biometric sensor Feature extractor Matcher Decision

A

Biometric sensor Pre-processing Feature Extractor Template generator

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28
Q

What is one of the new features that has been implemented with the NGI?
Sex offender registry status
Voice recognition
New Tenprint system
Gang affiliation

A

new tenprint system

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29
Q

What function of biometrics would law enforcement be implementing if they wanted to look for a person of interest accused of sexual assault in a large crowd at a sports stadium?

A

biometric matching or verification

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30
Q

Which scanners are largely outdated and considered to be too intrusive to be practical in real-world applications?

A

retina

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31
Q

Which of the following would not be considered a physiological biometric?
Voice
Fingerprints
Iris
Hand

A

voice

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32
Q

Which module is responsible for finding patterns in the traits extracted by the sensor using mathematical equations?

A

feature extraction

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33
Q

Which of the following technologies is replacing retina biometrics because it is an all-around better technology, which is functional for both law enforcement and business security.
Iris biometrics
Cornea biometrics
Sclera biometrics
Pupil biometrics

A

iris biometrics

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34
Q

Out of the various forms of behavioral biometrics, which of the following is the least accurate?
Handwriting
Voice recognition
Gait recognition
Keyboard dynamics

A

gait recognition

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35
Q

Which of the following systems is highly beneficial for law enforcement safety in that it allows for officers to fingerprint individuals they come into contact with quickly to detect whether or not they pose a potential threat?
RISC
NPPS
IPS
MorphoTrak

A

RISC

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36
Q

Which process captures a person’s biometric data and stores it in a database for later use?

A

enrollment process

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37
Q

What is the primary disadvantage with Principal Component Analysis?

A

a full frontal face image is needed to be a viable sample

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38
Q

Which of the following is not considered a behavioral biometric?
Facial scan
Gait Recognition
Keystroke patterns
Handwriting

A

facial scan

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39
Q

Which of the following features would not serve as a variable for analysis in biometric facial recognition?
Chin
Neck
Widow’s peak
Cheekbones

A

neck

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40
Q

What does the FBI’s acronym NPPS stand for?

A

national palm print system

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41
Q

Which of the following is not expected to show any evidential marks or impressions?
A fired bullet
A shotgun pellet
A cartridge casing fired from a handgun
A cartridge casing fired from a shotgun

A

a shotgun pellet

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42
Q

Tools and tool marks are often found at burglary scenes and can be useful evidence. Proper evidence collection by the field investigator would include:

A

taking a photograph and cast of the marks if necessary

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43
Q

The reason grooves are rifled into the bore of a gun is so that a:

A

bullet will be made to spin and have a true and accurate course on leaving the barrel

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44
Q

Distinctive markings of shells and cartridges can be made by what 3 things?

A

Firing pin
Extractor and ejector mechanism
Breech face mark

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45
Q

Which of the following factors is least likely to be considered by the examining tool mark technician?
The brand name of the tool
The angle at which the tool was held
The side or portion of the tool making the impression
The direction of the tool movement as it passes over the surface

A

the brand name of the tool

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46
Q

Which is NOT a class characteristic of a suspect’s sneaker?
Wear marks
Color
Size
Brand

A

wear marks

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47
Q

The likelihood of detecting GSR on swabs taken from living subjects more than six hours after a firing has occurred is ________ the likelihood of detecting GSR within two hours of a firing.

A

less than

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48
Q

Objects bearing tool marks should either be submitted intact to the crime lab or a ________ should be taken of the tool mark.

A

cast

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49
Q

Dust imprints found at a crime scene can be lifted using:

A

an electrostatic lifting device

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50
Q

The barrel of a shotgun:
Is generally shorter than that of a rifle.
Is wider at the end to concentrate shot.
Is indistinguishable from that of a rifle.
Is smooth without the grooves and lands found in rifles.

A

is smooth without the grooves and lands found in rifles

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51
Q

Generally, the gauge of a shotgun is ________ to the diameter of its barrel.

A

directly related

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52
Q

Which of the following results is not possible from a laboratory examination of firearm evidence?
-Restoring serial numbers ground off the gun
-Identifying a bullet as having been combined with a particular shell prior to being discharged
-Determining that two or more cartridge cases were fired from the same weapon
-Determining how far from the victim the weapon was held

A

identifying a bullet as having been combined with a particular shell prior to being discharged

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53
Q

Two-dimensional imprints found at a crime scene can be lifted using:

A

an electrostatic lifting device

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54
Q

Who makes the final determination about whether or not two bullets were fired by the same gun?

A

a trained firearms examiner

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55
Q

Which of the following procedures is not to be followed in collecting and packaging firearms evidence at the crime scene?
Marking an empty cartridge case on its base for identification
Marking a fired bullet on its base for identification
Avoiding inserting a stick or pencil into the barrel of a weapon
Unloading a weapon before shipping it to the crime laboratory

A

marking an empty cartridge case on its base for identification

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56
Q

Discharged evidence bullets must be carefully handled to avoid damage to the:

A

striation markings

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57
Q

When an etching agent is applied to a metal surface in order to restore a removed serial number the stamped area will dissolve at ________ as the unstamped area.

A

a greater rate

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58
Q

Generally speaking, the amount of gun powder particles found around a bullet hole is ________ to the distance from which the weapon was fired.

A

directly related

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59
Q

A wear pattern, cut, gouge, or other damage pattern can impart ________ characteristics to a shoe.

A

Indivuidal

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60
Q

The presence of gunpowder residues on a garment whose color conceals the existence of the residue is best revealed by:

A

infrared photography

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61
Q

Which is a true statement about the fracturing of glass?
-Radial cracks form afterward, starting on the same side as the destructive force.
-Concentric fractures form first, on the same side as the destructive force.
-Concentric fractures form first, starting on the side opposite the destructive force.
-Radial cracks appear first, starting on the side opposite the destructive force.

A

radial cracks appear first, starting on the side opposite the destructive force

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62
Q

To explain the events that occur after radiation is absorbed by a substance, light must be characterized as:

A

a stream of discrete particles

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63
Q

The fracture pattern of glass usually has:
Concentric lines.
Radial and concentric lines.
Directional lines.
Radial lines.

A

radial and concentric lines

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64
Q

Crystalline solids, with the exception of ________ crystals, exhibit ________, or the property of refracting a beam of light into two different ray components.
Amorphous, refraction
Calcite, refractive index
Cubic, double refraction
Glass, optical properties

A

cubic, double refraction

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65
Q

The process of a glass prism separating sunlight into component colors is called:

A

dispersion

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66
Q

The refractive index of a substance varies with:
Its temperature.
All of the above
The wavelength of the light passing through it.
The color of the light passing through it.

A

all of the above

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67
Q

The two most important physical properties of glass for forensic comparisons are:

A

refractive index and density

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68
Q

If glass cannot be physically pieced together then the control and question glass are best compared as to their:

A

refractive index and density

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69
Q

Sublimation is defined as a change of state from:

A

solid to gas

70
Q

The photons of which source have the LEAST amount of energy?
Microwaves
Gamma rays
Infrared rays
Radio waves

A

radio waves

71
Q

A hot-stage microscope or the GRIM 3 is used to determine the ________ of glass fragments.

A

refractive index

72
Q

________ is the visual effect caused by an object’s absorption of certain portions of the visible light spectrum and transmission or reflection of others.

A

color

73
Q

The smallest particle of an element that can exist and still retain its identity as that element is the:

A

atom

74
Q

When a bullet penetrates a panel of glass, it leaves a crater-shaped hole that:

A

is wider on the exit side

75
Q

A piece of glass is immersed in a liquid. It proceeds to float on the liquid’s surface. This shows that the density of the glass is ________ the density of the liquid.

A

less than

76
Q

Which physical state has volume but no specific shape?

A

liquid

77
Q

A(n) ________ property describes the behavior of a substance without reference to any other substance while a(n) ________ property describes the behavior of a substance when it reacts or combines with another substance.

A

physical; chemical

78
Q

Flotation is a method used by scientists to determine the ________ of a particle of glass.

A

desnity

79
Q

What three things can a fingerprint be classified as?

A

loops
whorls
arches

80
Q

What supreme court case challenged that fingerprints could not be proved unique under the criteria in the doubert case?

A

1999 US vs Mitchell

81
Q

What are fingerprints?

A

a reproduction of friction skin ridges

82
Q

What are minutiae?

A

ridge characteristics used to classify and match prints

it is the identity, number, and location of these that make a fingerprint indivuidal

83
Q

A fingerprint pattern stems from what layer of the skin?

A

papilae

84
Q

What is the most popular type of finger print pattern?

A

loop

85
Q

What is a unlar loop?

A

opens towards the little finger

86
Q

What is a radial loop?

A

opens towards the thumb

87
Q

All loops must have at least one what?

A

delta

a triangle looking pattern

88
Q

Whorls are divided into 4 groups caled:

A

plain
central pocket loop
double loop
accidental/mixed

89
Q

What do arches not have any of?

A

deltas

90
Q

What must a whrol have two of?

A

deltas

91
Q

What are the two categories arches are split into?

A

plain arches
tented arches

92
Q

What are the 4 steps in identifying and individualizing a fingerprint?

A

analysis
comparison
evaluation
verification

93
Q

What are the two biometric traits?

A

biological
behavioral

94
Q

What are two examples of biological traits?

A

finger prints and retinal scans

95
Q

What are two examples of behavioral traits?

A

handwriting and brainwaves

96
Q

What is total maginfication?

A

ocular magnification x objective magnification

97
Q

What does biofringent mean and what is an example of it?

A

split beams of light
fibers

98
Q

What is forensic palynology?

A

the collection and examination of pollen and spores connected with crime scenes, illegal activities, or terrorism

99
Q

What is the primary tool used in forensic palynology?

A

the mircoscope

100
Q

The raised areas of a gun barrel are known as ______ and the depressed areas are known as ______?

A

lands; groves

this is reversed when looking at a bullet REMEMBER THIS

101
Q

What is caliber?

A

the diameter of the gun barrel measured between opposite lands

102
Q

What are three ways to determine the class characteristics of a gun?

A

lands/groves (number and size)
twist
caliber

103
Q

What are striation marks?

A

lines formed on the inside of the barrel that translate on the bullet

provide indivuidal characteristics

104
Q

What is the primer cup?

A

the back of the bullet

105
Q

What is a bullet wipe?

A

the dark ring of GSR around the bullet hole

106
Q

What are properties and what are the type types?

A

the identifying characteristics of substances
chemical and physical

107
Q

What are examples of physical properties?

A

weight
size
color

108
Q

What is a chemical property?

A

the behavior of a substance when it reacts/combines with another substance

109
Q

What is often used instead of weight when comparing substances?

A

mass

110
Q

_____ is affected by gravity, ______ is not!

A

weight; mass

111
Q

What is a density?

A

an intensive property of matter

112
Q

What does it mean to be an intensive property?

A

the density remains the same regardless of the sample size

113
Q

What is refraction?

A

the bending of light waves because of a change in velocity

114
Q

What is refractive index?

A

the way light is bent

the ratio of the velocity of light in a vacuum to that in a medium under examination

115
Q

What is birefrigence?

A

taking the difference between the refractive indexes

116
Q

What is it called when the becke line disappears?

A

match point

117
Q

How do you know when you have reached a match point?

A

when the becke line disappears

118
Q

What is the difference between latent and patent print?

A

latent: requires extra work to see
patent: you can already see

119
Q

What is anthropometry?

A

the first system of ID using bodily meausrements

created by bertillonage

120
Q

What does iodine fuming do/used for?

A

revealing fingerprints while still allowing you to see the content under it

used for things like suicide notes

121
Q

What are dermal papillae and how are they important in fingerprinting?

A

the layer of skin between the epidermis and dermis

ridges in the skin that create the individual characteristics in a fingerprint

122
Q

Describe the difference between an arch and a tented arch.

A

a tented arch is taller and narrower than a regular arch

123
Q

Describe the difference between a pocket loop and a whorl.

A

a pocket loop is smaller and has a narrow tail
a whorl is wider (has more swirls) and has a wider tail

124
Q

What is the ACE-V method of matching prints? Describe/ explain each step.

A

A- Analysis (clarity of an image, look for possible distortions)
C- Comparison (compare questioned print on different levels)
E- Evaluate (identification, exclusion, inconclusive)
V- Verification (examiners conclusion checked against someone else’s)

125
Q

On what levels can fingerprints be compared? Explain and give examples.

A

3 levels

1- ridge patters
2- brifercations/minutiae
3- pores, skars, permanent minutiae

126
Q

What are three ways that we can prevent inaccurately matching fingerprints?

A
  • run it through NIBIN
  • double check it using ACE-V
  • make sure you have a good print and a complete match
127
Q

List and describe the three types of fingerprints that may be found at a crime scene.

A

patent - visible without processing
plastic - impressions on soft materials
latent - requires processing to become visible

128
Q

List two types of specialized fingerprint powders and name one advantage each has over traditional fingerprint powder.

A

fluorescent powder - bright under uv light and provides more contrast
small particle reagent (SPR) - a spray that is good for prints that are wet and are on moist, non porous surfaces

129
Q

What is the most commonly used chemical method to visualize latent fingerprints on porous materials? If this method is unsuccessful, what other technique typically is used?

A

ninhydrin

superglue fuming; iodine fuming

130
Q

What is digital imaging and how is it used in fingerprint analysis? What is the greatest limitation to digital imaging?

A

it can compare latent prints and enhance prints for easier comparison

131
Q

If you have an object that is wet, what methods could you use to develop the print? Why does this work?

A

small particle reagent (SPR)

it attaches to lipids and shows washed up or wet prints

132
Q

Be sure you can pick out the best method for developing prints in certain situations, such as a porous piece of paper, textured surface, etc.

A

porous - chemical
textured - physical

133
Q

What are the two main functions of biometrics? Be sure you can explain them.

A

1) matching and verification - ability to identify a criminal by using biometric characteristics
2) identification

134
Q

What are the two primary types of forensic biometrics? Be sure you can give examples of methods that fall into each category.

A

physiological biometrics - fingerprints, iris, retinal, and facial scans
behavioral biometrics - handwriting, voice, keystroke, gait recognition

135
Q

What is the first process that each biometric system must perform? What does it consist of?

A

verification and voluntary enrollment in the system

can ID someone using biometric characteristics

136
Q

What biometric system process or module performs most of the “heavy lifting” for the system?

A

feature extractor

finds patterns in the traits extracted by biometric sensors

137
Q

Which module is responsible for saving all the raw data produced by feature extraction and putting it into a simple and easy to read format for the system?

A

template generation - placed data in an easy to read format like a database

138
Q

What are some of the reasons why iris biometrics is replacing retina biometrics?

A

less invasive; more accurate; more individualized and permanent

139
Q

What is one significant advantage of automated facial recognition, as compared to other forms of biometrics such as iris and fingerprint systems?

A

it is non-invasive and does not require voluntary enrollment

140
Q

What is the difference between a real image and a virtual image?

A

real image - viewed directly
virtual image - magnified image seen through a lens

141
Q

Why does a compound microscope produce greater magnification than a magnifying glass? How does the eyepiece lens contribute to magnification?

A

it multiplies the magnification of the objective lens

can increase and decrease the magnification power

142
Q

What is vertical illumination and under what conditions would a forensic scientist use it to examine a sample? Why is it superior to transmitted illumination under such conditions?

A

used for opaque items
uses a stereoscope
when light comes from above and reflects off an object

143
Q

Why might an examiner choose a microscope with a lesser magnification to study a specimen?

A

want to see the whole specimen; larger field of view
less detailed objects need to be viewed

144
Q

When might you use a polarizing scope?

A

if the object scatters light (like crystals, soil, small minerals)

145
Q

When might you use a microspectrophotometer?

A

looks at how the object absorbs light (like counterfeit money, paint, and fibers)

146
Q

When might you use a scanning electron microscope?

A

use on a micro level to create an HD image with depth (like gun shot residue (GSR))

147
Q

How can a scanning electron microscope be used to determine whether a suspect has recently fired a gun?

A

reveals gun shot residue

148
Q

What is distance determination?

A

how far the shot was fired

149
Q

What is luminol?

A

a substance to look at impressions in blood

150
Q

What is a SEM stub?

A

a device used to catch molecules of gun shot residue

151
Q

What is rifling?

A

the spiral grooves cut in the gun causing the bullet to spin

152
Q

List some examples of class characteristics of a gun barrel.

A

lands
grooves
twist

153
Q

Describe how a firearms examiner compares two bullets. What characteristic does an examiner most often use to identify bullets and why?

A

striation marks
lands and grooves
twist
firing pin impressions
breech face matches

154
Q

List two reasons why striations on bullets fired from the same gun may vary slightly.

A

grit and rust inside the barrel
general wear and tear on the gun

155
Q

Besides the barrel, what parts of a firearm may leave distinctive markings on a shell cartridge?

A

ejector
extractor
firing pin
breech face

156
Q

List three characteristics of a bullet hole that indicate that the shot was fired at extremely close range.

A

GSR present
stellate star present
concentrated GSR pattern around the bullet entrance (dark rim)

157
Q

What evidence do investigators look for when trying to determine whether a suspect has fired a handgun? Where is such evidence typically found and why?

A

GSR present on the hands/clothing

158
Q

Describe how a criminalist restores an obliterated serial number on a weapon. Why is this an important forensic technique?

A

the metal there is already weakened so smooth the damaged area and apply an acid based solution which will reveal the numbers

159
Q

Name two types of marks that impart individuality to a tool and explain how the marks are made.

A

marks from the creation of the tool
marks from usage of the tool

160
Q

How would a forensic odontologist be able to determine that teeth were from a young child?

A

number of teeth
size of the mouth - shorter arch when younger

161
Q

Why is the metric system of measurement easier to use than the “English system”? Which system is used in the United States?

A

metric system is more standardized
americans use the imperial system

162
Q

Define the terms physical property and chemical property. Be sure you can give examples of each one.

A

physical - color, weight, volume, melting point
chemical - behavior of a substance, reactions, color test for drugs

163
Q

How does heat affect the density of gases and liquids?

A

as they are heated, the become less dense

164
Q

Define the terms refraction and refractive index.

A

refraction - bending the light - change way to see
refractive index - used when comparing things - measures refraction

165
Q

Define intensive property and name two intensive properties of matter.

A

something that doesn’t change density no matter how big the sample size is

color and temperature are two examples

166
Q

What is color? What determines the color of an opaque object?

A

color - how we see things in visible light

what wave lengths are being absorbed

167
Q

List two factors that make it difficult for criminalists to compare glass samples.

A

shatters too small
could be tampered with
too similar

168
Q

Describe the process of flotation and explain what it is used for.

A

puts objects in liquids with different densities and when it floats thats the density of the object (same as liquid)

used to determine density

169
Q

What is the Becke line and how is it used to determine the refractive index of a glass sample?

A

line around the pieces of glass when their refractive index doesnt match

when this disappears, that means there is a match point

170
Q

How can an investigator determine the order in which several successive penetrations of a glass occurred?

A

cracks - when one line stops at another

Forensic Science - 2023 (3 decks)

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