The fire cause has three elements of which a competent fuel source is not one of the three (3) factors. The competency is associated with the ignition source and evaluated in the context of the first fuel ignited.

At some point in the investigation of a fire consideration must be given to the hypothesis of an incendiary fire. One would endeavor to look for evidence of an incendiary fire. If evidence is found, then the accidental fire hypothesis is disproved and an alternative hypothesis can be formulated with this new evidence for a valid incendiary fire hypothesis.

You have suggested that there are those who believe that responsibility of this determination should be given to the public sector since they routinely collect evidence of motive, means, and opportunity. It is a very important tenet of fire investigation methodology that a determination of an incendiary fire must be made prior to and independent of evidence of motive, means, and opportunity. I believe the incendiary chapter provides some guidance on this.

The third consideration for a determination of fire cause is the identification of how the first fuel ignited came in contact with the competent ignition source for the first fuel ignited. Accidental fires can include human involvement. The same is true of an incendiary fire. Thus, human involvement is not uniquely consistent with either determination. Thus, it is human intent that is uniquely consistent with an incendiary fire. This needs to be determined before any use of motive, means, and opportunity that may be evidence collected by a public sector investigator. So who is in the best position to look for physical evidence of human intent (think Incendiary chapter) in the context of an origin and fire cause investigation?

Douglas J. Carpenter, MScFPE, CFEI, PE, FSFPE
Vice President & Principal Engineer
Combustion Science & Engineering, Inc.
8940 Old Annapolis Road, Suite L
Columbia, MD 21045
(410) 884-3266
(410) 884-3267 (fax)
www.csefire.com