RO Forensic Science & Analysis 2

Question 1

What is gunshot residue (GSR) primarily composed of?

Accepted Answer

Lead, barium, and antimony particles

Answer

GSR consists of microscopic particles of lead, barium, and antimony released from the primer upon firing.

Question 2

Which technique is considered the gold standard for confirming GSR on a suspect's hands?

Accepted Answer

Scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX)

Answer

SEM-EDX simultaneously identifies the morphology and elemental composition of individual GSR particles, making it the definitive confirmatory method.

Question 3

On a range incident scene, how should a spent cartridge case be collected to preserve forensic value?

Accepted Answer

Use gloves, pick it up by the rim, and place it in a labeled rigid container

Answer

Handling by the rim with gloves minimizes contamination of the case body where fingerprints and GSR may be present, and rigid containers prevent damage to extractor marks.

Question 4

What does 'chain of custody' mean in the context of range forensic evidence?

Accepted Answer

A documented, unbroken record of who handled evidence from collection to court

Answer

Chain of custody is the chronological documentation proving that evidence was not tampered with between collection and presentation in legal proceedings.

Question 5

Which rifling characteristic is most commonly used to link a recovered bullet to a specific firearm?

Accepted Answer

Land and groove impressions and twist rate

Answer

The number, width, and twist direction of lands and grooves are unique to individual barrels and are impressed on fired bullets.

(RO) Certified Range Officer Practice Test

(RO) Certified Range Officer Practice Test

RO Forensic Science & Analysis 2