Complex fire conditions can create fire patterns and burn damage that can be easily interpreted by the fire investigator as “multiple areas of origin”. For instance, the same full room involvement conditions that can lead to an incorrect single-area-of-origin determination can be easily misinterpreted as multiple areas of origin.
NFPA 921 (2014) 24.2.1 at 237
Multiple fires are two or more separate, nonrelated, simultaneously burning fires. The investigator should search to uncover any additional fire sets or points of origin that may exist. In order to conclude that there are multiple fires, the investigator should determine that any “separate” fire was not the natural outgrowth of the initial fire.
NFPA 921 (2014) 18.104.22.168 at 237
Fires in different rooms, fires on different stories with no connecting fire, or separate fires inside and outside a building are examples of multiple fire. A search of the fire building and its surrounding areas should be conducted to determine whether there are multiple fires.
NFPA 921 (2014) 22.214.171.124 at 237
Separate fires that are not caused by multiple deliberate ignitions can result from the following:
(1) Fire spread by conduction, convection, or radiation
(2) Fire spread by flying brands
(3) Fire spread by direct flame impingement
(4) Fire spread by falling flaming materials (i.e., drop down)
(5) Fire spread through shafts, such as pipe chases or air conditioning ducts
(6) Fire spread within wall or floor cavities within “balloon construction”
(7) Overloaded electrical wiring
(8) Utility system failures
(10) Rupture and launching of aerosol containers.
NFPA 921 (2014) 126.96.36.199 at 237
Apparent multiple points of origin can also result from continued burning at remote parts of a building during fire suppression and overhaul, particularly when building collapse or partial building collapse is involved.
NFPA 921 (2014) 188.8.131.52 at 237
The earlier a fire is extinguished, the easier it is to identify multiple points of origin. Once full-room involvement or room-to-room extension has occurred, identifying multiple fires becomes more difficult and a complete burnout or “black hole” may make identification impossible.
NFPA 921 (2014) 184.108.40.206 at 237
If there has been a previous fire in the building, care should be taken not to confuse earlier damage with a multiple fire situation.
NFPA 921 (2014) 220.127.116.11 at 237
Fire scene reconstruction (see Section 18.7), an important aspect of the fire scene examination, is especially important when multiple fires are suspected.
NFPA 921 (2014) 18.104.22.168 at 237
A careful examination of the fire scene may reveal additional fire sets that are intended to ignite additional fires, particularly in the same type of area. For example, if the investigator observes or discovers an area of origin in a closet, an examination of other closets for additional fires or fire sets is prudent. The investigator may be required to obtain legal authority to conduct a search in areas no affected or involved in the discovered fire.
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)
Gorbett G., Eliassen D., Kennedy P., Lentini J., Smith D., Report on the Peer Review of the Expert Testimony in the Case of State of Arizona v. Louis C. Taylor, Arson Review Committee.
George Souliotes v. Anthony Hedgpeth, Findings and Recommendation Regarding Statute of Limitations Issues
Commonwealth of Kentucky v. Robert Yell
State of Arizona v. Louis C. Taylor