An investigation is conducted to determine the origin, cause, and other factors that may have contributed to the ignition and growth of a fire.

Fire investigators conduct a fire investigation to compile data and analyze the information related to fires and explosions.

Investigation data is used to:

• reduce loss of life and property
• determine if a fire was intentionally set
• provide a basis of fact for after-fire legal processes
• identify trends
• develop public education programs
• develop codes and standards

The investigator's job is to determine the origin and cause of every fire after ruling out all possibilities of how and where the fire started. A systematic approach is used in processing every fire scene.

If possible, the investigator will document a fire scene with still photographs or video prior to the extinguishment of the fire.

When the fire scene is secure and safe for entry, the investigator observes and documents the scene while going from the area of least burn to the area of most burn.

The scene is secured until the time that the investigation begins, throughout the investigation, and until the scene is officially released back to the property owner.

If the fire is in a large occupancy or a multi-alarm fire, TVF&R utilizes investigation teams, dividing responsibilities such as:

• Interviews of witnesses, bystanders and first-in firefighters
• Processing the physical scene by examining the structure or scene for fire patterns and evidence
• Documenting the scene with photographs and diagrams
• Preserving and collecting evidence by maintaining the "Chain of Evidence" so it is clearly documented who has handled it, when, and why
• Feeding information to the Public Information Officers or acting in their behalf with both television and newspaper media

After the investigation is complete, the investigator is responsible for releasing the occupancy back to the property owners. The investigator may work with insurance adjusters and private investigators throughout the investigation.

Lastly, the investigator submits a report to their supervisor containing all information regarding the investigation in standard format. The investigator may be called on to testify in either a civil or criminal case with his or her conclusions concerning the investigation.

Investigators
An Investigator will spend a week at a time on duty from Monday to Monday and is on-call 24-hours per day, 7 days a week during their week of rotation.

Response Criteria
The Incident Commander is responsible for requesting the response of a fire investigator to the fire scene as per TVF&R's policy. The applicable criteria includes: arson fires, suspicious fires, undetermined causes, fatalities, fire injuries, total loss (excluding out buildings, sheds, etc), fires in institutional or educational occupancies, or as deemed necessary by the Incident Commander.

In addition a fire investigator is automatically dispatched to all working fires.

Notification
The investigators receive response requests via alpha-numeric pagers. The dispatcher may also call the investigator at home via telephone.