Systematic Analysis of Witness Statements for Fire Investigation

Abstract

Statements from witnesses to a fire are often crucial to the investigation of the fire. Given a large enough sample of witness statements, and by using a systematic approach to the analysis of witness statements, it is possible to provide a clearer picture of the events of a fire and assist in the determination of the fire origin, even when no witness observed the fire in the incipient stage. This paper presents a method for analyzing witness statements for fire investigations in the framework of the scientific method, as recommended by NFPA 921. This type of analysis is appropriate for testing fire origin hypotheses. A case study is presented involving a fire at a 129 unit apartment complex, for which interviews of over 90% of the apartment units are available. These statements have been condensed, mapped against a floor plan of the building, and analyzed such that fire origin hypotheses can be tested. The case study presented organized witness statements from a large fire incident in a manner that allowed the investigators to observe trends in the statements without discarding data that, at first, did not appear relevant or consistent with other statements.