Final answer:
Arson is suspected when a fire is characterized as incendiary or of an undetermined cause. Indicators of arson include accelerants, multiple origins, and the disabling of fire systems, aided by statistical fire activity data.
Step-by-step explanation:
Incendiary or undetermined fire:
Signs of arson are typically determined when the initial cause of a fire is indicated as D. incendiary or undetermined fire. Arson implies that the fire was set deliberately, as opposed to having a natural or accidental origin. Factors that might suggest arson include the presence of accelerants, multiple points of origin, or evidence of tampering with fire detection and suppression systems.
Arson investigators will also consider patterns of fire activity in the area, as indicated by data sources like police and fire departments, as well as any potential motives. These signs suggest that the fire was intentionally started or its cause cannot be determined. Arson investigations involve examining the scene for evidence of accelerants, identifying potential motives, and analyzing witness statements.