CMI Evidence Collection & Forensic Analysis 5 — Questions and Answers
Question 1: 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?
- Review of diving regulations and decompression tables
- Detailed evidence identification protocol including what to document, what not to disturb, photography sequence, and artifact collection prioritization (Correct answer)
- Weather forecast and sea state report
- Vessel owner contact information for post-dive reporting
Correct 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.
Question 2: What is the primary purpose of conducting a 'negative autopsy' in a marine drowning investigation where no anatomical cause of death is identified?
- To confirm the victim was in good health prior to the incident
- To exclude other causes of death and support a drowning diagnosis by demonstrating the absence of findings inconsistent with drowning (Correct answer)
- To establish the exact time of death for insurance purposes
- To collect tissue samples for environmental contamination testing
Correct 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.
Question 3: 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?
- Power off the device and store it in a waterproof evidence bag
- Place the device in a Faraday bag to block wireless signals while maintaining power, preventing remote access (Correct answer)
- Upload the data to a cloud service for secure storage
- Remove the battery to prevent continued power consumption
Correct 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.
Question 4: 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?
- Vessel age and original build specification drawings alone
- Actual load distribution, fuel and ballast levels, free surface effect of liquid cargo, and comparison against the stability booklet's approved loading conditions (Correct answer)
- The vessel's gross tonnage and beam measurement only
- Captain's estimate of the list angle before capsizing
Correct 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.
Question 5: During a fire investigation, an investigator finds multiple independent, non-connected points of origin. What does this pattern most strongly suggest?
- The fire self-propagated through an HVAC system connecting the areas
- Multiple points of origin are a strong indicator of incendiary (arson) fire unless a single credible accidental explanation connects all points (Correct answer)
- The fire suppression system malfunctioned and spread burning suppression agent
- Natural lightning strike commonly causes multiple simultaneous ignition points
Correct 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.
Question 6: 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?
- The pump's maintenance log entries from the past year
- Microstructural analysis of the pump components to identify heat-affected zones, oxidation patterns, and whether failure indicators predate fire exposure (Correct answer)
- The fuel oil sample from the last bunkering operation
- Testimony from the chief engineer regarding pump performance
Correct 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.
Question 7: 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?
- Only the vessel master is required to file a report
- The owner, operator, and master are each individually required to file written reports with the nearest Marine Safety Office within five days (Correct answer)
- Only the vessel owner must report; the master's testimony substitutes for a written report
- Reports are only required if the Coast Guard initiates a formal hearing
Correct 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.
CMI Evidence Collection & Forensic Analysis 5
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?