Ok, lets take Section 24.2. I believe this can all be supportive evidence but in and of itself is questionable. The first part of the investigation is to identify the location of the fire(s) origin. From their there must be a determination as to the fuel that was ignited. The best part of this section is that it warns the investigator not to jump to conclusion as to the fire being set just due to the belief there were separate fire. It gives you information as to some possible reasons for the separate fire and tells the investigator these must be eliminated before this evidence can be used to support a set fire.

I know negative corpus is a touchy subject, but is not 24.2.4 just that when it comes to lack of expected fuel load. What is considered an expected fuel load. In most cases, the fuel load at the origin location has not been document when the investigation is taking place. This means any conclusion as to the lack of expected fuel is subjective and not fact when this is taking place. Yes, if there is a confirmed list of what was at that location before the fire the investigator has a starting point when going through the debris. How does the investigator scientifically determine what amount of this expected fuel was consumed by the fire?

Now there is 24.3 – Potential Indicators Not Directly Related to Combustion. I believe the title of this section tells us that these items have nothing to do with the cause of the fire or its spread. This is where the old red flag idea comes back into the document. This is strictly motive and intent. Going back to the committee’s statement as to why they removed classification, 921 does not instruct the user as to how to determine intent, Here again I am not taking a side as to it being here but just saying if you delete classifications for the reason given then this section should also be deleted.

Section 24.4 – Other Evidentiary Factor is the same, which is consistency with the committee’s statement as to the removal of classification. Here the understanding of the meaning of the word incendiary. What is an incendiary fire? Is it a criminal act? I believe most people would have that understanding of the term. What is wrong with saying the fire resulted as the result of human interaction. What are the classification of fires as they were in 921 before this edition? Accidental was fires not involving an intentional human act to ignite or spread fire into an area where it should not be. Natural Fire Causes is something that everyone understood as being something like lightning or other natural event. Undetermined is just what it means, That leaves us with incendiary. The definition for incendiary includes intent. So when section 24.4 states the fire must be determined to be incendiary before these additional evidentiary factors can be considered. This is telling the user one must determine the intent of the person before the investigator should even consider the items listed yet the items listed are there to assist in proving intent. You may say that these are additional items that will support the intent determination and you would be right. No matter what, according to the statement made in this section these items have nothing to do with determining the cause of the fire. If the NFPA has decided this document does not instruct the investigator on intent then why are there areas dealing with intent. As the word incendiary was defined in the prior editions, it was meant to insinuate a criminal act. I would ask the investigator to show what evidence was there to determine the fire was a criminal act without using the areas discussed in sections 24.3 and 24.4. If the investigator has sufficient evidence then all the items in these two sections are nothing more than icing on the cake.

Jim Mazerat
Forensic Investigations Group