NCJ Number
82980
Journal
Fire and Arson Investigation Volume: 32 Issue: 3 Dated: (January - March 1982) Pages: 13-18
Date Published
1982
Length
6 pages
Annotation
This article discusses the investigation of structural fires in which all combustibles have been consumed; techniques of the arsonist and proper investigation procedures are emphasized.
Abstract
In arson investigation, a structure which has been completely consumed by fire is termed 'black spot.' Reasons for complete consumption include insufficient water supply, structural composition of highly flammable materials, or the presence of flammable liquids. Upon arrival at such an investigation, the investigator should not assume that all evidence has been destroyed by fire; all equipment necessary for investigation should be brought to the scene. Photographs showing the vantage points of the four corners of the building should be taken. A thorough search of the area should be conducted for containers discarded by the arsonist. Footprints and tire impressions should be taken, particularly in rural communities. A low order of explosion normally occurs when a volatile liquid has been used and has reached the explosive limit prior to ignition. Glass blown from a building is a good indication that a flammable liquid was used. When evaluating the interior of the structure, particular care must be taken regarding noncombustibles such as metal. As there are many variables affecting the thermal stress factor, it is important to know what the building contained prior to the fire. The person who discovered the fire is the most important witness to interview. The investigator must learn not only the basic theory of fire but also those variables which will change or affect burn patterns. The article includes two photographs.