What steps should be taken to determine the area of origin of a fire?

To effectively determine the area of origin of a fire, starting from the exterior and moving to the interior is the most logical approach. This method allows investigators to first assess the building's exterior and any visible damage, which can provide critical information about the fire's path and intensity. By analyzing the exterior, investigators can identify burn patterns, smoke stains, and any evidence of an ignition source before entering the building.

Once inside, the investigator can then examine the interior space methodically, looking for indicators such as charring, heat damage, and the arrangement of items, which can further help pinpoint where the fire started.

This systematic approach ensures that all potential clues are considered and helps in ruling out areas that may have been affected by the fire but are not its origin. An understanding of fire behavior and the effects of ventilation, fuel sources, and materials is also essential in this process. Moving inward from the exterior provides a comprehensive view of how the fire developed and spread, which is crucial for accurate investigation and analysis.