Although the fundamental methodology of fire-pattern and fire-dynamics analysis provided in NFPA 921 and other texts appears to provide some guidance to assist the investigator in determining a fire’s area of origin, the reliability and validity of this method has not been rigorously measured. Of special concern is the accuracy of area of origin determination in a ventilation controlled compartment fire.
NFPA 921 (2014) 18.1 at 186
Introduction. This chapter recommends a methodology to follow in determining the origin of a fire. The area of origin is defined as a structure, part of a structure, or general geographic location within a fire scene, in which the “point of origin” of a fire or explosion is reasonably believed to be located. The point of origin is defined as the exact physical location within the area of origin where a heat source and the fuel interact, resulting in a fire or explosion. The origin of a fire is one of the most important hypotheses that an investigator develop and tests during the investigation. Generally, if the origin cannot be determined, the cause cannot be determined, and generally, if the correct origin is not identified, the subsequent cause determination will also be incorrect. The purpose of determining the origin of the fire is to identify in three dimensions the location at which the fire began.
NFPA 921 (2014) 18.1.2 at 186
Determination of the origin of the fire involves the coordination of information derived from one or more of the following:
(1) Witness Information. The analysis of observations reported by persons who witnessed the fire or were aware of condition present at the time of the fire.
(2) Fire Patterns. The analysis of effects and patterns left by the fire (See Chapter 6.)
(3) Arc Mapping. The analysis of the locations where electrical arcing has caused damage and the documentation of the involved electrical circuits (See Section 9.10.)
(4) Fire Dynamics. The analysis of the fire dynamics, that is, the physics and chemistry of fire initiation and growth (see Chapter 5), and the interaction between the fire and the building’s systems (See Chapter 7.)
NFPA 921 (2014) 18.2 at 186
Overall Methodology. The overall methodology for determining the origin of the fire is the scientific method as described in Chapter 4. This methodology includes recognizing and defining the problem to be solved, collecting data, analyzing the data, developing a hypothesis or hypotheses, and most importantly, testing he hypothesis or hypotheses. In order to use the scientific method, the investigator must develop at least one hypothesis based on the data available at the time. These hypotheses should be considered “working hypotheses,” which upon testing may be discarded, revised, or expanded in detail as new data is collected during the investigation and new analyses are applied. This process is repeated as new information becomes available.
NFPA 921 (2014) 184.108.40.206 at 191
Consideration of All Patterns.
Law Review Articles
Folklore and Forensics: The Challenges of Arson Investigation and Innocence Claims, P. Tafti and P. Bieber, 119 W. Va. L. Rev. 549 (2016)
Steven W. Carman, Improving the Understanding of Post-flashover Fire Behavior, Proc. of the Int’l Symp. on Fire Investigation Science and Tech., (2008)
Steven W. Carman, Progressive Burn Pattern Development in Postflashover Fires, Proceedings of Fire and Materials, (Interscience Comm., London, UK, 2009)
Steven W. Carman, Science Trumps Art in Fire Investigation, 74(7) Texas Bar Journal 587 (July 2011)
Andrew T. Tinsley & Gregory E. Gorbett, Fire Investigation Origin Determination Survey, Proc. of the Int’l Symp. on Fire Investigation, Science and Tech. (2012), 53-68
State of Wisconsin vs. Joseph Awe, Circuit Court in and for Marquette County, No. O7-CF-54 (see Decision and Order of the Hon. Richard O. Wright, 03/21/2013)
United States v. James Hebshie, Criminal No. 02cr10185-NGsee Memorandum and Order re: Motion to Vacate Conviction, Hon. Nancy Gertner (11/15/2010)
State of Arizona v. Louis C. Taylor
State of Arizona v. Ray Girdler, 675 P.2d 1301, 138 Ariz 482 (Ariz 1983)