In fire investigations, what is often analyzed to detect the presence of an accelerant?

In fire investigations, the presence of accelerants is a crucial aspect of determining whether a fire was intentionally set. Unconsumed flammable liquids are specifically analyzed because they are the substances that can cause a fire to ignite and spread more rapidly than it would with ordinary combustible materials alone. During an investigation, if there are residues of these flammable liquids that remain unconsumed after a fire, they can indicate that an accelerant was used.

The analysis typically involves using techniques such as gas chromatography to identify chemical signatures associated with known accelerants, which helps investigators ascertain whether foul play is involved. This approach provides vital evidence in not only proving the presence of an accelerant but also in potentially identifying the type of accelerant used.

While blood samples and soil samples can provide relevant information in various investigations, they do not directly indicate the use of accelerants in a fire. Similarly, tool mark evidence is more related to determining whether specific tools were used to create certain marks or damage and does not pertain to the analysis of accelerants involved in a fire. Therefore, focusing on uncontested flammable liquids is the most pertinent method for detecting accelerants in fire investigations.