ETC Crime Scene Processing 3

Question 1

The 'Locard Exchange Principle' is most directly relevant to crime scene processing because it states that:

Accepted Answer

When two objects contact each other, trace material is exchanged

Answer

Locard's principle holds that every contact between a person and a scene results in the transfer of trace material in both directions.

Question 2

A technician is casting a tire track in soft soil. Which material is most commonly used?

Accepted Answer

Dental stone (die stone)

Answer

Dental stone is preferred over plaster of Paris for tire and shoe impression casting because it is harder, more durable, and captures finer detail.

Question 3

Which action would MOST compromise the integrity of digital evidence found on a computer at a crime scene?

Accepted Answer

Powering on the computer to check its contents

Answer

Powering on a computer can alter timestamps, overwrite temporary files, and activate encryption, destroying critical digital evidence.

Question 4

At an outdoor homicide scene, what environmental factor poses the greatest threat to trace DNA evidence?

Accepted Answer

UV radiation and moisture

Answer

UV radiation breaks down DNA strands and moisture accelerates microbial degradation, making them the primary environmental threats to trace DNA.

Question 5

When should a crime scene log (scene entry/exit record) be initiated?

Accepted Answer

Immediately upon securing the scene

Answer

The scene log must begin as soon as the scene is secured to record every person who enters or exits from that point forward.

(ETC) Evidence Technician Certification Practice Test