The investigation of a fire scene begins after the firefighters have extinguished the fire. Fire investigations are conducted by qualified experts who have the vision, knowledge and deep understanding of fire science. It is one of the most dangerous and complicated types of investigation as searching for evidence in the recently burnt area can prove to be hazardous. It is complicated as the fire continuously alters and destroys evidence as it burns. Determining the origin of fire can be very difficult as the observation of damages is independent of the path taken by the fire. Forensic science means applying scientific methods and processes to solve crimes. The basic fundamentals of forensic science are used in and fire investigations. This allows the experts to know the origin and cause of the fire.
The first thing an expert must know to conduct a fire investigation is:
Knowledge of chemistry, physics, the behavior of fire, and the effects of it
This is the scientific knowledge involved in explosion and fire investigations.
Fire occurs due to the exothermic reaction of combustion, producing heat and light. In order for a fire to occur, three vital components must be present:
A fuel source
A sufficient amount of energy in the form of heat
Heat produced during a fire can spread in three ways:
Convention- this transfers heat via air circulation, only occurs in liquids and gases.
Conduction- this transfers heat through a medium by direct contact
Radiation- this transfers heat through a medium by direct contact, such as heat of the fire can ignite a nearby sofa.
- Behavior and effects of fire
The fire can show different patterns and behavior depending on its nature. The flames may have varying colors, the fire may or may not show smoldering, sometimes spontaneous combustion occurs. The effects of a fire may also be varying, it can cause from a small scale to very large scale damage.
Collection and analysis of data using scientific methods and required instruments
This is the most important aspect of any investigation, same goes for a fire investigation. The scientific method involved in a fire investigation is:
- Identify the problem: the root cause is to be determined by the occurrence of the unfortunate event
- Collection of data: the evidence and data have to be collected efficiently from the crime scene. This is a crucial step and must be conducted with thorough precautions and sincerity. No evidence should be misplaced or tempered.
- Analyse the data: the data and evidence once collected can be used for analysis. This has to be done without mere speculations.
- Develop a hypothesis: after the analysis is completed, a hypothesis or multiple hypotheses can be framed considering all possibilities.
- Test the hypotheses: the various hypotheses must be put to test using high-level equipment and required knowledge.
- Select final hypothesis: the hypothesis which stands out must be selected.
Fire investigations conducted using fundamentals of forensic science by experts generate good results. It makes it possible to know the origin and cause of a fire and hence, in bringing justice to the affected individuals.