The Fire and Arson Investigation Unit works with local, state and federal investigators to determine the origin and cause of a fire. The SBI has original jurisdiction in fire and arson cases. 

SBI fire investigators may classify fires as accidental, providential (natural) or incendiary (intentional). If investigators are unable to conclusively determine a single possible cause of the fire, then the fire will be classified as undetermined. If the fire is determined to have been incendiary in nature, investigators may assist in the second area of fire investigations. In this area, agents may assist local, other state and federal investigators to determine who is responsible for setting the fire.
 
When fully staffed the Fire and Arson Investigations Unit consists of 17 agents who are specially trained to conduct fire investigations.  Each District Office is assigned two agents along with a statewide program coordinator who oversees the administrative and logistical aspects of the program.

The SBI has at least one investigator on call at all times in an attempt to maintain 24-hour statewide coverage.
 
One of the most important tools used by some fire investigators to assist in the investigations is an accelerant detection K-9. These canines are specially trained to detect minute amounts of petroleum-based products commonly used to set fires. The SBI has several accelerant detection K-9s that respond to scenes across the state. This canine program started in the mid-1980s, making it one of the oldest on-going Accelerant Detection K-9 programs in the country.