Origin & Cause Determination Flashcards
7 cards from real CFI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Origin & Cause Determination flashcards as text
Which condition must exist for spontaneous ignition to be considered a valid fire cause?
Answer: The material must be capable of self-heating, conditions must allow heat to accumulate faster than it dissipates, and the temperature must reach ignition point
Spontaneous ignition requires a material capable of oxidative self-heating, an environment where heat accumulates faster than it dissipates, sufficient mass to sustain the process, and eventual attainment of ignition temperature.
When investigating a vehicle fire, what is the most reliable method for determining origin?
Answer: Systematic examination of fire patterns on vehicle components, burn depth, and protected areas to trace convergence to a point of origin
Vehicle fire origin is determined by systematically examining fire patterns, protected areas, burn depth, and component damage to identify the convergence point of fire patterns.
What is the investigative significance of 'protected areas' in fire pattern analysis?
Answer: Protected areas show less fire damage because an object shielded them, helping reveal the fire's direction and origin
Protected areas reveal where objects shielded surfaces from heat or flame, creating shadow patterns that help investigators determine fire direction, intensity, and potentially the origin area.
An investigator finds that the fire scene has collapsed floors and ceilings. What technique does NFPA 921 recommend for layered debris analysis?
Answer: Systematic removal of debris in layers, documenting the location and depth of fire patterns at each level
NFPA 921 recommends systematic layered excavation of debris, documenting fire patterns, artifacts, and evidence position at each depth to reconstruct fire behavior and identify the origin.
A cold-weather fire investigation reveals frost or ice on interior surfaces away from the area of origin. What does this observation potentially indicate?
Answer: The presence of frost indicates those areas were not exposed to significant heat, helping define the fire's spread boundaries
Frost or ice on interior surfaces indicates those areas experienced little or no heat during the fire, helping investigators define the boundaries of fire involvement and narrow the area of origin.
In cause determination, what distinguishes an 'incendiary fire' from an 'accidental fire'?
Answer: An incendiary fire is one intentionally set; an accidental fire results from unintentional ignition without criminal intent
An incendiary fire is deliberately set with intent, while an accidental fire results from unintentional action or circumstances without criminal intent, regardless of damage level.
What is the investigative value of examining the 'first fuel ignited' in cause determination?
Answer: It helps link the competent ignition source to the fuel, establishing a logical and physical connection necessary to determine fire cause
Identifying the first fuel ignited is essential because it must be physically connected to the competent ignition source; together they form the fire cause hypothesis that must be supported by physical evidence.