“If you have multiple competent ignition sources for the same fuel, then you have multiple fire cause hypotheses. If you do not have a fire cause hypothesis that is uniquely consistent with the available evidence, your fire cause hypothesis is "undetermined." “

This is where I have problems understanding based on common sense. If one knows there was a fire, then it is obvious that there was a fuel the was ignited by a competent ignition source. There does not need to be a determination as to what was the fuel ignited or what was the source of ignition for this to be a fact. The same is true if one knows the fuel that was ignited but does not know the ignition source. It is a fact that this fuel was ignited by a competent ignition source or there would not have been an ignition of the fuel. So, the fire cause hypothesis that this fuel was ignited by a competent ignition source must be correct because it is a fact that the fire took place. The only thing that is undetermined is what was the specific source of ignition.

“I am not sure I understand your point of this example. This is not a fire cause hypothesis, where you have identified each element of the fire cause with evidence in this specific incident. What you have done is really define what a fire cause is.”

The point of this example is that one can have a valid hypothesis as to how and why a fire took place without there being a specific competent ignition source identified.

The point I am wanting others to consider is that there are times when facts present themselves that will allow one to reach a conclusion. If all I have is a burned down building, I can have a valid hypothesis that a fire took place. If one identifies the fuel first ignited there can be a valid hypothesis that the fuel was subjected to a competent ignition source. A person does not need to know the first fuel ignited and the specific source of ignition to have a valid hypothesis.

Jim Mazerat
Forensic Investigations Group