Forensics trace evidence test

Question 1

Which of the following is not a layer of the hair shaft?

Answer 1

follicle

Question 2

The layers of the hair shaft are the _____________, the ____________, and the _____________.

Answer 2

cuticle, cortex, medulla

Question 3

Which part of the hair shaft is most resistant to chemical decomposition?

Answer 3

Cuticle

Question 4

Which feature of hair is MOST important in making a species identification?

Answer 4

Scale Pattern

Question 5

The number of hair scales pointing towards the tip of the hair is __________ the number of hair scales pointing towards the hair follicle.

Answer 5

greater than

Question 6

A cast of a hair surface can be made using:

Answer 6

clear nail polish, softened vinyl

Question 7

Pigment granules that impart hair with color are found in the

Answer 7

The cortex

Question 8

The central canal running through many hairs is known as the

Answer 8

Medulla

Question 9

The medullary index of human hair is ___________ the medullary index for most other animals.

Answer 9

Less than

Question 10

Medullae may be classified as being

Answer 10

all of the above

Question 11

A hair sample was examined and its medulla appeared to have a pattern described as resembling a string of pearls. It was most likely from a

Answer 11

Cat

Question 12

In making hair evaluations, it is best to view the hairs using a ___________ microscope.

Answer 12

Comparison

Question 13

Microscopic hair comparisons must be regarded by police and courts as:

Answer 13

Presumptive

Question 14

In what stage can a hair most readily be removed from the scalp?

Answer 14

Telegenic

Question 15

The rate of human hair growth per month is:

Answer 15

1 cm

Question 16

Beard hairs are coarse and normally ________ in cross-section.

Answer 16

triangular

Question 17

A human hair in cross-section appeared flat in shape. The ancestral origin was most likely

Answer 17

African

Question 18

In determining whether a hair sample originated from a male or a female, the MOST important consideration is

Answer 18

the results of DNA analysis performed on the root structure.

Question 19

The presence of sheath cells on hair that has been pulled quickly from the head is ________ the presence of sheath cells on hairs that have been removed slowly from the scalp.

Answer 19

Greater than

Question 20

The stages of hair growth include all of the following EXCEPT

Answer 20

Analgesic

Question 21

Nuclear DNA typing can be most successfully accomplished on hairs that have been removed during which stage of growth?

Answer 21

Anagenic

Question 22

The conviction of Ennis Cosby’s killer was aided by the DNA analysis on a hair that was crucial evidence in the case. This hair

Answer 22

belonged to the killer and was found in his cap with which he had wrapped the murder weapon before discarding it.

Question 23

Before the 20th century, all fibers were

Answer 23

natural

Question 24

Which type of crime is LEAST likely to be solved with the use of fiber evidence?

Answer 24

Bombing

Question 25

Mohair and cashmere are hairs from:

Answer 25

Goat

Question 26

By far the most prevalent plant fiber is:

Answer 26

Cotton

Question 27

A fiber whose microscopic appearance includes being ribbon-like in shape (flat) with twists at irregular intervals is

Answer 27

cotton

Question 28

What was the first man-made fiber?

Answer 28

Rayon

Question 29

A regenerated fiber can be derived from

Answer 29

Acetate

Question 30

Which is NOT a manufactured fiber?

Answer 30

all of the above

Question 31

Which is made of natural polymers?

Answer 31

sand

Question 32

The monomers involved in the synthesis of proteins are:

Answer 32

Amino Acids

Question 33

Cellulose is the basic component of

Answer 33

Wood

Question 34

It is a virtual certainty that two fabrics share a common origin if their fibers

Answer 34

Can be fitted together at their torn edges

Question 35

Wayne Williams was convicted of serial murder mainly on the strength of

Answer 35

fiber evidence

Question 36

Which of the following properties should NOT be examined when comparing two synthetic fibers?

Answer 36

Medullary index

Question 37

The visible light microspectrophotometer is a convenient tool with which to compare the color of fibers because

Answer 37

All of the above

Question 38

Synthetic fibers display __________ because they are crystalline

Answer 38

Birefringence

Question 39

Generally, the parallel refractive index of a fiber is __________ the perpendicular refractive index of the same fiber.

Answer 39

Greater than

Question 40

During the collection of fiber evidence, great care should be taken to

Answer 40

avoid cross-contamination of evidence

Question 41

What type of evidence would be expected to have trace elements?

Answer 41

All of the above

Question 42

The knowledge that elements selectively _______ and ________ light provides the basis for important analytical techniques designed to detect the presence of elements in materials.

Answer 42

absorb, emit

Question 43

A _________ shows distinct frequencies or wavelengths of light.

Answer 43

line spectrum

Question 44

In a simple emission spectrograph, excitation of the specimen under investigation is accomplished with a(n):

Answer 44

electrical arc

Question 45

The nucleus of an atom contains:

Answer 45

Protons and neutrons

Question 46

Atoms having the same atomic number but different atomic masses are called

Answer 46

isotopes

Question 47

Which type of radiation is NOT given off by radioactive decay?

Answer 47

x-rays

Question 48

Beta particles are identical to

Answer 48

electrons

Question 49

Neutron activation analysis involves bombarding specimens with neutrons and then measuring the resultant

Answer 49

Gamma rays

Question 50

Which of the following is a nondestructive technique for identifying and quantifying trace elements in a test sample?

Answer 50

Neutron activation analysis

Question 51

Paint as physical evidence is most frequently encountered in

Answer 51

A & B

Question 52

Which is NOT part of the composition of paint?

Answer 52

adhesive

Question 53

Which property imparts paint with its most distinctive forensic characteristics?

Answer 53

color layer sequence

Question 54

Paint binders can be chemically analyzed using:

Answer 54

B & C

Question 55

Pyrolysis gas chromatography is a particularly valuable technique for characterizing paint’s:

Answer 55

Binder

Question 56

The elements that comprise the inorganic pigments of paint can be identified by

Answer 56

all of the above

Question 57

An element is selective in the frequency of light it will absorb. This selectivity is due to its

Answer 57

electron energy levels

Question 58

After examining small paint chips from an auto accident scene and using the PDQ database, the crime lab worker can determine the __________ of the vehicle.

Answer 58

All of the above

Question 59

What is the logical first step in soil analysis?

Answer 59

examination for presence of debris under low-power magnification

Question 60

In most cases, the _________ layer(s) of soil is/are picked up during the commission of a crime.

Answer 60

top

Question 61

Which would be LEAST useful in identifying a mineral crystal?

Answer 61

Color

Question 62

Soil found on the suspect, such as that adhering to a show or garments, ____________ be removed.

Answer 62

Must not

Question 63

During the investigation after the assassination of President Kennedy, elemental analysis of the silver and antimony content classified the bullets and fragments recovered (6 in total) into ________ distinctly different groups

Answer 63

2

Question 64

Most soils can be differentiated by its

Answer 64

gross appearance

Question 65

Crime labs are often asked to identify the make and model of a car from a small amount of paint and will make use of color charts for automobile finishes for the __________ database.

Answer 65

PDQ

Question 66

Many manufactured products and even most natural materials contain small quantities of elements, known as trace elements, present in concentration of ________________.

Answer 66

Less than 1%

Question 67

Forensic analysis has employed neutron activation on trace elements found in

Answer 67

metals, drugs, paint, soil, hair, and gunpowder residue

Question 68

Minerals in soil can be characterized by their (select all that apply)

Answer 68

All of the above

Question 69

Paint chips are most likely found on or near persons or objects involved in

Answer 69

Hit and runs

Question 70

In most cases, only the top layer of soil is picked up during the commission of a crime, so standard samples should be removed from the surface - only about ____________ is sufficient.

Answer 70

1 tablespoon