ETC Trace Evidence 2

Question 1

Which analytical technique is most commonly used to determine the chemical composition and polymer type of fiber evidence?

Accepted Answer

Fourier transform infrared spectroscopy (FTIR)

Answer

X-ray diffraction (XRD)

Answer

Gas chromatography alone

Answer

Atomic absorption spectroscopy

Question 2

When collecting soil samples as comparison trace evidence, what is the correct procedure?

Accepted Answer

Collect samples from multiple locations including control areas away from the scene

Answer

Collect only from the exact location where the suspect stood

Answer

Take a single large sample from near the victim

Answer

Skip soil collection if the ground is dry

Question 3

What microscopic index value helps differentiate human hair from most animal hair?

Accepted Answer

Medullary index

Answer

Cortical cell ratio

Answer

Pigment density index

Answer

Cuticle scale count

Question 4

What is gunshot residue (GSR) primarily composed of, and why is it significant as trace evidence?

Accepted Answer

Lead, barium, and antimony particles unique to firearm discharge

Answer

Carbon and nitrogen compounds indicating smokeless powder

Answer

Iron oxide and copper from the bullet jacket only

Answer

Nitrates and nitrites from the propellant gases

Question 5

Which tool is most appropriate for collecting dry, loose trace evidence such as glass fragments or paint chips from a surface?

Accepted Answer

Forceps or fine-tipped tweezers

Answer

Moistened cotton swab

Answer

Adhesive tape roller

Answer

Stiff-bristle brush

Question 6

What forensic value do glass fracture patterns provide in a crime scene investigation?

Accepted Answer

They can indicate the direction and sequence of multiple impacts

Answer

They permanently trap DNA from the person who broke the glass

Answer

They reveal the exact weight of the object used to break them

Answer

They identify the specific brand of glass manufacturer

Question 7

In trace evidence searches, which area of the crime scene should generally be examined first?

Accepted Answer

The most volatile area likely to be disturbed or where evidence could be lost

Answer

The center of the crime scene where the main event occurred

Answer

Entry and exit pathways only

Answer

The perimeter boundary of the scene