Expert fire investigators know the limits of arc mapping as an indicator of fire origin. Concerns about arc mapping are on the rise. There are doubts associated with arc-related artifacts, distinguishing “cause” from “victim” beads, visual vs. microscopic examinations, and even practitioner qualifications. Specific noteworthy complaints include: (1) overpromises on the technique’s precision, (2) exaggerated inferences from the available data, (3) failure to adequately account for potential methodological flaws, (4) deficient scientific rigor in establishing evidentiary fire origin-related reliability, (5) errors due to deficient practitioner training and experience, and (6) indeterminate findings based upon subjective visual analysis. An emerging industry of pseudoscientific expert witnesses compounds these problems. Untrustworthy and invalid fire-related arc mapping clothed as forensic science continues to invade the courtroom.
Tom R. May & David J Icove,
Arc Mapping Methodologies & The Pursuit of Magical Globules, Notches, & Beads: A Bridge too Far to Establish Fire Origin?,
Lincoln Mem’l U. L. Rev.
Available at: https://digitalcommons.lmunet.edu/lmulrev/vol7/iss2/2