Deck 10: Trace Evidence

Question 1

Which of the following will influence the density of a substance?

A) thermal history
B) chemical composition
C) state of matter
D) all of the above

Answer 1

D

Question 2

Which of the following phases of hair growth characterized the last phase in which the hair is naturally shed?

A) telogen
B) anagen
C) catagen
D) haragen

Answer 2

A

Question 3

Comparing of refractive indices of glass is often done by the ____ method.

A) float
B) submersion
C) cohesion
D) immersion

Answer 3

D

Question 4

In collecting paint evidence from a hit and run accident, ____.

A) collect all layers of the evidence sample and the top layer nearby for a reference sample
B) collect all layers of the evidence sample and all layers nearby for a reference sample
C) collect the top layer of the evidence sample and the top layer nearby for a reference sample
D) collect the top layer of the evidence sample and all layers nearby for a reference sample

Question 5

Which of the following parts of a hair contains the hair pigment?

A) cuticle
B) cortex
C) follicular tag
D) medulla

Question 6

The scale pattern of a hair can be visualized by ___.

A) SEM
B) Impression in fingernail polish
C) Birefringence
D) Cross-section of the hair
E) Both a. and b.

Question 7

Which of the following is the long growth phase of a hair which can last up to six years?

A) anagen
B) telogen
C) methogen
D) catagen

Question 8

Which of the following is a natural fiber?

A) Dacron
B) rayon
C) polyester
D) cotton

Question 9

A fracture line in glass from a second impact ____ terminate at an existing line fracture.

A) will
B) will not

Question 10

Which of the following is true for collecting paint evidence?

A) Tools used to gain entry into buildings or safes often contain traces of paint, requiring the tool be collected.
B) Paint can be collected in new glass or plastic vials.
C) Uncontaminated reference paint must always be collected taken from near point of contact.
D) Paint must be collected down to the metal surface using a scalpel.
E) All of the above.

Question 11

Which of the following is the correct order of the layers of paint is delivered by the manufacturer on an automobile?

A) Electrocoat primer, primer surfacer, basecoat, clearcoat
B) Electrocoat surfacer, clearcoat, primer, basecoat
C) Clearcoat, basecoat, electrocoat primer, primer surfacer
D) Clearcoat, electrocoat primer, basecoat, primer surfacer
E) Primer surfacer, clearcoat, basecoat, electrocoat primer

Question 12

Which of the following is a non-destructive technique that is first used to evaluate hair and fiber evidence?

A) make a cast to view the scale pattern
B) visualization with a stereomicroscope
C) DNA typing analysis or the root
D) cut with a razor to view the cross-section

Question 13

Which of the following parts of a hair is the central column?

A) cuticle
B) cortex
C) follicular tag
D) medulla

Question 14

Sketch a diagram and label five parts of a human hair.

Question 15

What microscopy method is used to examine synthetic fibers? Explain why.

Question 16

Briefly explain how hairs differ in morphology from synthetic fibers such as acetate and Dacron.

Question 17

What features of a paint chip can be used to individualize the sample?

Question 18

Diagram two bullet holes and label the types of cracks that are typically present and how to determine the sequence of the bullets shot.

Question 19

Define birefringence.

Question 20

Explain how ATR FT-IR spectroscopy can be used to identify unknown fibers and polymers.

Question 21

Can hair and animal fibers be individualized? Explain your answer.