Fire Investigation skills are a combination of understanding how fires start and what the typical indicators look like to be able to identify not only the area of origin, but also the point of origin. Once these two facts are established, usually by eliminating all other possible areas of origin and focusing in on the specific point of origin and what factors could have started the fire and which only contributed to the fire growth and spread.
The challenge that most “arson investigators” face in forensic fire investigations, is that they have very little experience in explaining non arson fires. Without the fundamental understanding of combustion and fire physics along with the ability to understand and explain non arson causes of fire, such as electrical circuit overloads and short circuits, it becomes very difficult to explain to a jury why a combustible material does not need to reach 750 degrees F, to cause a fire. As an example, fine dry wood shavings ignite at about 325 degrees F. Wiring insulation is a plastic or polymer, and acts a lot like a combustible liquid, when heated. All the vapors need are oxygen and a spark or glowing metal surface to ignite. Such fires start off very small, usually smaller than a birthday candle, but rapidly grow into major fires under the right conditions.
Once the investigation is commissioned, does the investigator use NFPA 921 as a guide for conducting a investigation? Does the investigator know how to conduct a “scientific examination and investigation”? While the client may not need or want a complete fire investigation report, never the less, an investigation must follow the protocols in NFPA 921. What the client may be asking for is simply a declaration. A statement of the experts opinions, that can be backed up with science.