Arc Mapping: Who and Why?

  • Rick Forte
  • John Frucci
  • Ashley Keener Oklahoma State University

Abstract

Background: In 2020, the National Fire Protection Association (NFPA) released the 2021 edition of NFPA 921: Guide to Fire and Explosion Investigations. In this new edition, the technique of arc mapping is no longer considered one of four methods to determine the area of origin of a fire (NFPA, 2017) but instead has been reclassified as a fire pattern. This reclassification is a product of diverging opinions among experts in fire investigations.

Methods: A survey tool was circulated to 98 fire science professionals to examine diverging perspectives associated with arc mapping. The survey instrument contained 11 questions and sought to identify trends in arc mapping’s use, success, and acceptance among the fire investigation field.

Results: Trends identified include: a correlation between training specific to arc mapping and the frequency of consideration, an increased frequency of use by private sector investigators, and a direct relationship between the use of arc mapping and the availability of resources. Finally, when considering these practitioners’ experiences, the respondents’ rate of success can be estimated at 78%.

Conclusion: A review of literature was used to outline the arc mapping principle most widely accepted among fire investigators.  Similarly, the results of the survey tool provided insight into why investigators consider using arc mapping, what factors are considered when using arc mapping, and how this technique is used.

Published
2021-12-13
Section
Forensics