Structure and Evaluation of the Process for Origin Determination in Compartment Fires

The science behind the formation of fire patterns and their ensuing use in the forensic analysis of fire scenes has been questioned since their introduction in the 1940s. This paper provides an overview of a prototype method for determining the area of origin based on fire patterns analysis, named the process for origin determination (POD). The POD is a seven step reasoning process for evaluating fire damage, which starts by identifying the value in further analysis of each surface and compartment of a structure and then procedurally evaluates each surface for use within the overall determination. This paper outlines the application of the POD with test subjects and presents an analysis of the outcomes showing its benefits. To facilitate testing the POD, numerical simulations and physical experiments were employed. The numerical simulations were completed through the use of fire dynamics simulator simulating a single compartment measuring 3.66 m x 3.66 m x 2.44 m with a single ventilation opening. The physical experiments were tests conducted specifically for fire patterns where accuracy rates had been previously identified in the literature. Sixty test subjects participated in the evaluation of thirty-two different origin scenarios. A decrease in variability, which indicates an increase in reliability, was noted in 21 of the 32 scenarios (66%) when participants used the POD. Three accuracy measurements were employed, all three of which illustrated an increase in accuracy when participants used the POD. The accuracy was shown to increase between 50% and 94% when participants used the POD.