Contained in the paper [1] are statements that need correction. Specifically, the following:

“Recently, the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) published a description of an arc mapping method that they apparently had been teaching at in-house classes, although they had not published it previously.”

This refers to statements made in the Fire Research Laboratory’s (FRL) Technical Bulletin Number 2 [2] to highlight what was perceived as an oversight in Dr. Babrauskas’ analysis of tests conducted by West and Reiter. Ellipses were used in the technical bulletin to highlight a fundamental problem with not fully considering the impact of circuit topography within the test compartments. This “ellipse method” was not a proposed new methodology to be used in the process of examining a structure’s electrical system, and is not taught in any ATF curriculum.

We appreciate the opportunity to clarify this issue, as arc mapping is a continuing topic of debate within the fire investigation community. It is important that everyone in the industry have an accurate understanding of current practices, and continue improving on the methodologies used in forensic science, including fire investigation.

Sincerely,

ATF Fire Research Laboratory

Bureau of Alcohol, Tobacco, Firearms and Explosives