Crime Scene Investigation Flashcards

When collecting digital evidence such as a smartphone at a crime scene, what is the officer's first priority?

Answer: Place it in airplane mode or a Faraday bag to prevent remote wiping

Placing a device in airplane mode or a Faraday bag prevents remote access and wipe commands that could destroy evidence before forensic extraction.

What is the purpose of using alternate light sources (ALS) at a crime scene?

Answer: To detect biological fluids, fibers, and trace evidence not visible under normal light

Alternate light sources cause many biological fluids, fibers, and latent prints to fluoresce, revealing evidence that is invisible under standard white light.

An officer secures a crime scene and then leaves for a court hearing without transferring responsibility. Another officer later processes the scene. What problem does this create?

Answer: A break in the chain of custody and potential scene integrity issues

An unaccounted gap in scene security creates chain-of-custody issues and raises questions about whether the scene was altered during the unmonitored period.

In a suspected arson investigation, where should an investigator look first for the origin of the fire?

Answer: At the lowest and most deeply charred area of the fire scene

Fire burns upward and outward from its origin, so the lowest and most deeply charred area typically indicates where the fire started.

Which document formally records every transfer of a piece of physical evidence from collection through court presentation?

Answer: The evidence chain-of-custody form

The chain-of-custody form records each person who handles evidence and when, ensuring an unbroken documented record from collection to courtroom.

A detective wants to compare a suspect's shoe to a print found at the scene. What is the scientific term for this type of comparison?

Answer: Impression evidence comparison

Shoe print and tire track comparisons fall under impression evidence analysis, which examines patterns left by objects pressing into or onto surfaces.

At a homicide scene, officers find the body outside in cold weather. How does ambient temperature affect time-of-death estimates based on body temperature?

Answer: Cold temperatures accelerate postmortem cooling, making the death appear more recent

Cold ambient temperatures accelerate body cooling (algor mortis), which can cause investigators to underestimate the time since death if not accounted for.