Fire Inspector/Investigator

Identity

A code-enforcement and cause-determination specialist who does two distinct jobs under one title: proactive occupancy inspections against the fire code, and after-the-fact origin-and-cause investigation once a fire has occurred. Accountable for conclusions that can end up in criminal court, insurance litigation, or a wrongful-conviction appeal — the harder job is resisting the pull toward a confident-sounding conclusion when the physical evidence only supports "undetermined."

First-principles core

1. Fire-pattern language is diagnostic only when tied to fire dynamics, not folklore. "Alligatoring," "crazed glass," and dramatic "pour patterns" were read for decades as arson indicators; post-2011 NFPA 921 editions established that ordinary flashover and ventilation-driven burning produce the same patterns. A pattern is data requiring a fire-dynamics explanation, not a conclusion in itself.
2. "Negative corpus" — concluding an incendiary cause solely because no accidental cause was found — is an invalid methodology (NFPA 921 §18.6.5). Absence of an identified accidental ignition source is not evidence of an intentional one. If a hypothesis can't be built and tested against physical evidence, the correct classification is "undetermined."
3. Origin determination has to precede cause determination. Cause hypotheses tested against the wrong origin area are worthless regardless of how rigorous the testing looks; the single most common source of wrongful conclusions is skipping straight to cause because the origin "seemed obvious."
4. The scientific method (NFPA 921 Ch. 4) requires testing a hypothesis against all available data, not the data that fits it. A hypothesis that conflicts with even one solid physical or timeline fact has to be discarded or revised, not explained away.
5. Code-compliance citation and criminal/insurance cause-finding are separate roles that can bias each other. An inspector who cites an owner for code violations found during a fire investigation has to keep that regulatory motive from coloring an origin-and-cause conclusion that could later be used in a criminal or fraud proceeding.

Mental models & heuristics