I think you can find the proficiency test can be found in NFPA 1033. In there you will find the job performance requirements. It list both requisite knowledge and skills. There are also test that one can take from the IAAI that fills this requirement. Here you can be tested in the areas of fire investigation, fire investigation technician, motor vehicle fires, evidence collection, and instructor. These test your level of proficiency in each category. What you get from this is a certification from an independent agency stating you met the proficiency requirements of a national accepted standard.

Now let’s talk about the bias. I have been on both sides of this issue. After 48 years what I have come up with is bias creeps in to the investigation in many different ways. Separating the cause determination from the investigation into motive and intent can help avoid bias. This does not mean that bias still cannot work its way in to the investigation. This is where the investigator must understand that if he chooses to do both there will be a challenge where bias will come up. You just need to be prepared to deal with it. As the investigator, you need to be able to show how you followed the scientific method when determining the origin and cause of the fire. Show how without any of the information on motive or intent you came up with the conclusion. When challenged, I have had my attorney take it backwards. Started removing each motive or intent and after doing it show the jury how if they take this information out and they follow your method of determining the cause they would reach the same conclusion as to the cause.

One challenge of bias I have seen for years is the fact you are an arson investigator and it is your job to find arson. Many of the fire departments still call their unit arson investigation units. Dose this mean this investigator can only determine if a fire is arson. Juries see this as ridiculous. In talking to the people on the jury after the trial I have found out this more times than not works against the person doing the questioning.

Now comes the hard one, the mystical error rate. What is an error rate? An error rate is a known or estimated measurement that can be used to represent the validity of a method. There are many different types of error rates. There are practitioner error rate, instrument/ technological error rates, statistical error rate and method/technique error rate.

If error is misunderstood or misrepresented, it can have serious legal and scientific consequences. Reasons for misunderstanding or misrepresentation vary. As there are a number of types of error rates there are also different error rates. There is the zero error rate. This is where they are trying to lead you as the investigator. Even with finger prints, there is no zero error rate. This not saying that there is more than one person with the same fingerprint but it saying that there or other reasons, such an in the interoperation or number of matching point that can lead to an error. No expert should try to establish a zero error rate. The next thing to be careful about is indicating no error rate can be determined. To stay away from these two pitfalls one should admit there is always an error rate. The error rate in each case and by each investigator is different. There is not a set error rate that is acceptable for the generic fire investigation. What can be said that the scientific method has been accepted by the scientific and that by following that methodology it reduces the potential error rate. It is at this point when your explanation as to how your investigation was conducted using the principles of the scientific method supports you having as low as possible error rate.

Hope this answers some of the questions.

Jim Mazerat
Forensic Investigations Group