Describe some of the principal investigative steps in determining whether a vehicle fire is accidental or arson.

Question

What will be an ideal response?

Answer 1

Along with the general increase in crimes in the United States has come an increase in automobile fires. Many of the criminal fires occur when stolen vehicles have been stripped of valuable parts and the rest is burnt to destroy the evidence. However, as in other fire investigations, the investigator first must eliminate natural and accidental causes of fire.
Before beginning the physical investigation of a vehicle fire scene, the investigator must understand that the crime scene examination includes both the vehicle and the area in which it was burned. Hence, the investigation must follow established principles by first recording the scene. Photographs should be taken immediately, before there is any disturbance of the crime scene. Measurements must be taken to establish the exact location of the vehicle in relationship to fixed objects, crossroads, houses, and so on. A description should be noted regarding the terrain, nearby roadways, and weather conditions (including prevailing wind directions). A thorough search should be made of the area for tire-tread marks, footprints, cans, bottles, other containers, unusual residue or materials, old tires, matches, or any other item that may be related to the case. Samples should be taken of soil, which may contain evidence of flammable liquids. When found, each item should be photographed before being moved, and then it should be properly packaged and marked as evidence. An inspection of the salvage must be completed for information on the origin and possible motive for the fire. Generally, investigators inspect the burnt automobile before contacting the owner, and the inspection is made as soon after the fire as possible. The inspection starts where the fire apparently originated. In accidental fires, this will normally be the part of the vehicle that is the most badly damaged from the intensity of the heat.
Accidental fires usually spread in diminishing degrees from the point of origin according to prevailing conditions. Conditions include direction and velocity of wind and/or materials on which flames feed, such as gasoline in the tank, woodwork, or other similarly flammable parts of the vehicle. When there are significant variations in these patterns, arson emerges as a possibility. Arson fires started with flammable materials usually show intense heat in more than one place. The investigator should carefully note the extent of the fire and its path. This information may prove valuable in the later questioning of the owner or witnesses. The car also should be inspected for the removal of equipment such as stereo, heater, air horns, fog lights, and so forth. Notice should also be made of other irregularities such as old tires on new cars or missing spare tires.