Scene security is extremely important during any fire investigation. It is important for local authorities to remember that if a State Fire Marshal investigator will be requested, the scene should be kept as free of contamination as possible and overhaul operations should be limited to affected areas.
To properly secure a fire scene, entry must be limited to only those authorized personnel with duties in the structure. Personnel should be posted at all points of entry into the structure to keep unauthorized individuals out. It is particularly important that the scenes of fatal fires be secured until the investigation has been completed. Many times, the area surrounding the victim may contain valuable evidence. This entire area should be preserved until the investigator determines all evidence has been collected.
If an investigator will be assisting, evidence should be left where it is found unless there is a possibility of further destruction by fire. If local personnel seize evidence, it must be secured in unused air-tight metal or glass containers.