Accurate wildland fire origin and cause determination is an essential first step in a successful fire investigation. Proper investigative procedures which occur during initial attack can more accurately pinpoint fire causes and preserve valuable evidence that might be destroyed by suppression activities. If a fire is human-caused, the protective measures described in the guide can preserve evidence that may lead to effective and fair administrative, civil, or criminal actions.

The investigation should start at the time a fire is reported or discovered. First responders play an important role in protecting evidence, so it is important for the wildland fire investigator to help train first responders to identify and protect the General Origin Area of the fire. Wildland fire investigators should impress upon firefighters, law enforcement officers and other first responders that the preliminary protection of the General origin area and any associated evidence on any wildfire is their responsibility, and emphasize to them that they are the most important link in the subsequent origin and cause determination. Not only is it important for the first responders to recognize the need for an accurate origin and cause determination, it is important that they understand how their actions, both during and following suppression, can enable a qualified wildland fire investigator to accurately determine the origin and cause.