Let’s look first at the history of classifying the causes of fires. The main question in the beginning was the need to determine if a fire was intentionally set. This related to the criminal aspect and the working addressing fraud in the insurance policy. This continued for hundreds of years.

In 1973, there was a report published under the title “America Burning”. The report was issued by the National Commission on Fire Prevention and Control. The report was based on a 2-year study. They study indicated that the fire chiefs in many of the largest cities believed that half of all the fires they experience was intentionally set. This was a call to action in both the private and public sector. I was one of the beneficiaries of the study. My job in the fire service changed and I was placed in charge of fire investigations and one of the largest just parishes (counties) in the state. I was paired up with state investigators as well as agents from the Bureau of Alcohol Tobacco and Firearms. This federal agency was just starting to expand into the area fire investigations. It was a requirement to classify all fires as being arson (incendiary), accidental or undetermined. The unit I was assigned to was renamed from fire prevention to arson investigation. Looking back, I can see that classification was being used not only to justify the funding of the unit but to increase funding to the fire service with the goal of reducing the number of arson fires.

When I started in the private fire investigation business at the end of the 70’s, classification was being used to show the client (insurance industry) the effectiveness of the company’s investigations. Because classification was in our reports, we were being asked to justify the classification in depositions and court testimony and at times to point a finger directly at the insured. I did not at the time realize how dangerous was this process.

Let’s face it, our classifications during the early years was not based on science. I had an instructor who is very prominent in both the public and private sector tell me he could determine if a male person said a fire by the way he stood at the urinal. He was proud of the number of arson classifications he produced.

Bolstering the idea that most fires were being intentionally set was the book published in 1972 by Dennis Smith, “Report from Engine Company 82”. Mr. Smith talked about all the structures in the Bronx that would being intentionally set for one reason or another. I’m not saying these fires were not being intentionally said but one of the people classify the causes was the same individual they can make a determination by just watching a person use the restroom.

There was a push during the 70’s and up to today to have the engine companies classify the cause of the fire. These were people with good intent but little to no training to make this determination. It was obvious that classification was being used to justify the existence of these arson units.

I stopped using a cause classification in the late 90’s, so what was done in 921 did not affect how I describe what took place. What I started doing was identify fuel(s) in the area where ignition took place and then address the source of heat producing ignition. This caused me grief within my own company when the management demanded that we needed to classify all the fires we investigated.


During the time I was on the original 921 committee I always had a problem with classifications. One of the first examples was the stove top fire. How does one know the thoughts of the person that leaf the burner or the element in the on position? It was a must to know this if there was to be an accurate determination.

The next step in the evolution was if the classification was based on science or on one’s opinion. Can intent always be proved through science. This was hard on many of the old-timers to agree with the concept pf needing to prove all point of the investigation through science.

Another point came to light. This was the fire service was still using a classification system and this system was not only different from what was found in 921 but in some ways better. I the fire service their investigators were required to classify the cause of all fires they responded to based on the information found in NIFRS. NFPA 921 did not go into all the questions found in NIFRS before a classification could be made. 921 has not said it is wrong for an investigator to classify the cause of a fire. It just suggests there is a different document to guide the investigator in reaching a classification

NIFRS has a good methodology for an investigator to use if they want to feel the necessity to classify the cause of the fire.

The company I am with today does not use the three classification that was found in NFPA 921. If the science indicates that there was human involved in the ignition sequence then it is explained in plain words.

Jim Mazerat
Forensic Investigations Group