Fire and explosion investigation practice and reporting
This domain tests the practical side of a CVFI investigation: scene safety, evidence handling, interviews, report writing, and defensible opinions. The exam rewards conclusions that are documented, limited to the data, and expressed at the right level of certainty.
Core practice
- Secure the scene before examining it: high-voltage batteries, undeployed airbags, fuel, pressurized cylinders, unstable structures, and hazardous fluids are immediate risks.
- Preserve and document evidence with photographs, video, sketches, measurements, and an evidence log; maintain chain of custody for samples and components.
- Interview owners, drivers, witnesses, and first responders, separating direct observations from opinions and rumors.
- Write reports that state scope, methodology, data reviewed, analysis, origin, cause, limitations, and supporting evidence. Use plain language and avoid boilerplate.
- Keep opinions within your qualifications and the evidence. Distinguish fact, inference, and opinion; do not overstate certainty.
- Retain case files and evidence according to policy and legal requirements, and disclose limitations that could affect the conclusion.
Worked example
A report states: “Origin: left rear cargo area. Cause: undetermined.” The support includes burn patterns, witness statements, and a laboratory result negative for ignitable liquids. Reasoning: the origin is defensible because multiple independent data point to the same area. The cause remains undetermined because the battery pack is destroyed, the electrical system cannot be energized for testing, and no ignition source can be confirmed. This is stronger than naming a cause without affirmative evidence, and it gives the client a clear basis for further examination.
Traps that cost marks
- Writing a confident cause without documenting the evidence and exclusions.
- Breaking chain of custody or failing to record sample blanks.
- Using generic report language that does not tie conclusions to this vehicle.
- Ignoring safety hazards or returning to a scene before it is stabilized.