"I agree that human involvement can be involved in the determination of a fire cause. I do not feel that just from the process of determining a fire cause will give an investigator sufficient evidence as to the person’s intention. Just saying human involvement was involved cannot in and of itself support a classification. A classification cannot be reach without the evidence of the person’s intent. To me that is a different type of investigation. I would say in most cases this activity is conducted by the public sector. There is a small percentage conducted by the private sector."

Can be? It is part of the definition of a Fire Cause in 921. If there is no evidence of an intent to start a fire where one was not going to occur, otherwise, then it is an accidental fire. When evidence of intent is found (think Incendiary Chapter), then a valid hypothesis of an incendiary can be formulated. Remove intent and you will always have an accidental fire cause.

Please explain how this is a different type of investigation? Before a crime can be determined to have occurred, there needs to be a determination of an incendiary fire.

"Yes, I do believe a chapter on incendiary fires is appropriate. There are many of those that use 921 are also responsible for determining a person’s intent. The methodology used is what has been used in investigations for years to determine intent. I agree this methodology is done mostly in criminal investigations, but it is also done in some civil investigations. This methodology deals with the preponderance of the evidence."

As it is incorporated into 921, how is this information of practical use to the FI following NFPA 921?


"As I said before, I believe the term “Intentionally” in a chapter titled “Incendiary” it gives one the perception of a criminal activity. There needs to be some explanation that they are not necessarily talking about a criminal act. If the investigation is being conducted to determine if the person’s intent was to commit a criminal act the there will be evidence of motive and opportunity. I believe first must come the fire cause and then the activity to prove intent."

A criminal act is based on a determination of an incendiary fire. An act versus the law.

For reliability (see Incendiary Fire chapter), one cannot reliably use evidence of motive, means, and opportunity as evidence of an incendiary fire. This evidence is reliably use only after a determination of an incendiary fire has taken place.

I challenge anyone to explain how the current edition fo NFPA 921 can be used to charge a person with Arson. If subsequent investigation is required outside of NFPA 921, please explain what needs to be determined and what evidence is reliably applied to reach a reliable determination.

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