Evidence Collection & Forensic Analysis Flashcards

A commercial fishing vessel sinks in 60 feet of water. Before divers are sent to survey the wreck for evidence, what pre-dive briefing element is most important from an investigative standpoint?

Answer: Detailed evidence identification protocol including what to document, what not to disturb, photography sequence, and artifact collection prioritization

Divers must know exactly what to look for, what to leave in place, and how to document findings before entering the water, as the underwater environment limits communication and re-entry opportunities.

What is the primary purpose of conducting a 'negative autopsy' in a marine drowning investigation where no anatomical cause of death is identified?

Answer: To exclude other causes of death and support a drowning diagnosis by demonstrating the absence of findings inconsistent with drowning

A negative autopsy in drowning cases confirms that no injuries, disease, or toxicological findings explain death, making drowning the most probable cause by exclusion.

An investigator recovers a waterproof GPS device from a casualty scene. What forensic step must be taken immediately to prevent remote data wipe or alteration?

Answer: Place the device in a Faraday bag to block wireless signals while maintaining power, preventing remote access

A Faraday bag blocks all radio frequency signals including cellular, Wi-Fi, and Bluetooth, preventing remote wipe commands while keeping the device powered so volatile data is not lost.

When documenting stability evidence after a capsizing casualty, which combination of factors is most critical to establish the vessel's condition at time of incident?

Answer: Actual load distribution, fuel and ballast levels, free surface effect of liquid cargo, and comparison against the stability booklet's approved loading conditions

Capsizing analysis requires knowing the actual loading state — including free surface effects — compared against the approved stability criteria to determine whether the vessel was operated within safe limits.

During a fire investigation, an investigator finds multiple independent, non-connected points of origin. What does this pattern most strongly suggest?

Answer: Multiple points of origin are a strong indicator of incendiary (arson) fire unless a single credible accidental explanation connects all points

Multiple unconnected points of origin that cannot be explained by fire travel pathways strongly suggest deliberate ignition at each location.

An engine room fuel injection pump failure is suspected as the cause of a vessel fire. Which type of evidence would a metallurgical expert examine to determine whether the pump failed before the fire or was destroyed by it?

Answer: Microstructural analysis of the pump components to identify heat-affected zones, oxidation patterns, and whether failure indicators predate fire exposure

Metallurgical analysis can distinguish between pre-fire mechanical failure (wear patterns, fatigue, lack of fire oxidation on fracture surfaces) and fire damage to an intact pump.

Under 46 CFR Part 4, which parties are required to submit a written report to the USCG following a serious marine incident involving a commercial vessel?

Answer: The owner, operator, and master are each individually required to file written reports with the nearest Marine Safety Office within five days

46 CFR Part 4 imposes separate reporting obligations on the owner, operator, and master, each of whom must independently file a written report within the prescribed timeframe.