10 free, exam-style Certified Fire Investigator (IAAI CFI) practice questions with answers and explanations. No signup required. Work through them below, then take the full free IAAI CFI practice test to study every exam domain.
Investigators find irregular, sharply bordered burn patterns on the floor of a room that reached full involvement (post-flashover). Standing alone, what do these patterns establish?
Correct answer: B - Nothing conclusive; they require laboratory corroboration
An investigator eliminates every accidental cause in a room and, with no accidental explanation remaining, classifies the fire as incendiary - yet identifies no ignition source, first fuel, or ignition sequence. This reasoning is improper because it relies on:
Correct answer: C - The negative corpus (elimination without supporting data)
A 1,500-watt space heater is connected to a standard 120-volt branch circuit. Using P = I × V, approximately how much current does it draw?
Correct answer: A - 12.5 amps
At the autopsy of a victim recovered from a structure fire, the medical examiner documents soot within the trachea and lower airway. This finding most strongly indicates that the victim:
Correct answer: D - Was alive and breathing during the fire
A fire in a closed room appears to diminish and nearly self-extinguish, then sharply intensifies the moment firefighters force open the door. This behavior is most characteristic of a fire that was:
Correct answer: A - Ventilation-controlled before the door was opened
A natural-gas leak has filled a room to a concentration well above the gas's upper explosive limit (UEL). At this exact moment, the atmosphere is:
Correct answer: C - Too rich to ignite, but may become ignitable as it dilutes
An investigator observes a network of short, web-like cracks (crazing) in window glass. According to current fire investigation science, crazed glass is most reliably associated with:
Correct answer: B - Rapid cooling, such as from a hose stream
An investigator collects fire debris suspected of containing ignitable liquid residue. To preserve the volatile evidence for laboratory analysis, the sample should be packaged in:
Correct answer: D - A clean, unlined metal can or vapor-tight container
In a jurisdiction that follows the Frye standard, the admissibility of scientific expert testimony turns primarily on whether the underlying technique or theory:
Correct answer: C - Has gained general acceptance in the relevant field
Examining wiring, an investigator finds a copper conductor with a smooth, rounded bead and a sharp line of demarcation between affected and unaffected metal. Standing alone, what does this arc bead establish?
Correct answer: D - That electrical activity occurred there, but not that it caused the fire
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