Collecting Data

After the questions are understood, and before the actual collection of data, analysis is performed to identify the data needed and to design methods of collection. This may be as straightforward as organizing inspection equipment and data collection checklists or it may be complicated by the need to design disassembly protocols that maximize documentation of conditions.

In fire investigation, even moving materials without the use of tools can disturb important evidence. During one investigation of the total burn non-collision fire of a van with interior engine access, careful removal of debris revealed that the remaining metal edge of the polymeric engine cover was displaced at the floor level. Interviews later revealed that the driver had engine trouble. While driving he had the engine cover set back so he could adjust the carburetion while on the road. The documentation of the precise engine cover position led directly to the identification of the cause of fire. Without a step-wise process of inspection and data collection, key evidence would have been lost.

Data collection may also include ancillary sources, such as service manuals, witness interviews, collection of reports and logs from emergency service agencies, and vehicle service history. These sources, when available, often provide valuable information.