What do arrow patterns indicate in a fire investigation?

Arrow patterns in a fire investigation serve primarily to indicate the direction of fire spread. This visual representation helps investigators understand how fire propagated through a structure, which is essential for analyzing the fire dynamics and identifying potential causes.

While it’s true that investigators look at fire patterns on structural materials to assess fire behavior, arrow patterns specifically are a distinct representation typically utilized to illustrate directional pathways of heat and flames as they move through an area. They can show where the flames traveled and potentially help in focusing on areas of interest for further investigation.

Understanding arrow patterns is crucial for reconstructing the events leading up to and following ignition, as they also assist in determining whether the fire was accidental, deliberate, or the result of other factors. These insights are vital in formulating hypotheses regarding the fire's origin, ultimately contributing to a thorough analysis based on NFPA 921 guidelines.