The Fire Officer’s Responsibilities at Incendiary Fires

Jan. 10, 2011
The fire officer hold responsibility in assisting the fire investigation units at the scene.

I would like to discuss the fire officer’s responsibility in assisting the fire investigation units at the scene. Many times the fire department is the first agency to arrive at the incident and the actions taken by the officers and the members of the fire suppression companies can either help or hinder the investigation. Indicators of an incendiary fire can be detected by officers and firefighters by being alert and making observations. The officers and firefighters are the investigator’s eyes and ears prior to his or her arrival. The fire may be in an area or district that the investigator is not familiar with and the company officer may be able to provide the investigator with a wealth of information. The building or area may have been the site of previous fires and a pattern of firesetting may be starting to develop. The relationship between the fire investigation unit and the fire suppression companies is critical to the outcome of the investigation.

Size-up and Outside Observations

It’s important to remember the fire inspections or pre-plans that your company has done over the years in your district. The information gained from previous inspections is invaluable. During inspections, your company is able to become familiar with the type of construction, fire protection systems, interior layout and building services, and any hazards associated with the occupancy.

Here is an example of how important inspections are. Early in my career, I was working for a fire bureau as an inspector and inspected a clothing business three times. The business had a number of minor violations that were cited and all violations were abated in a few weeks. The business had a triangle floor display that was approximately four-feet wide and six-feet high and was used for customers to stand behind and try on clothes. A few months after my inspections, a fire was reported in the rear office of the store and the contents were destroyed. I was on the first due engine and our crew made the initial interior attack. The triangle floor display was placed in a location to prevent the fire department from gaining access to the rear of the structure. During the trial, I testified to this fact. Before the end of the trial, the owner of the store admitted to intentionally setting the fire.

Fire officers and firefighters that arrive first at the scene are in an excellent position to make critical observations for an investigator who is not on the scene. When the fire is reported, all officers conduct a size-up. Size-up is an evaluation of conditions and problems that affect the outcome of the incident. This size-up begins the moment the alarm is transmitted. Remember, that size-up is an information-gathering process.

During the response, be observant of any automobiles or persons leaving the scene or acting in a suspicious manner. This is especially important if the fire is in an isolated area. The fire officer should try to get a description of the vehicle and occupants. Note any blocked or any damaged fire hydrants or blocked access to the scene. Note the way the occupants are dressed. If it’s three in the morning and everyone is fully dressed and the structure is fully involved ask yourself why. Make sure you note any comments by the occupants or bystanders. Make sure you scan the crowd or bystanders and look for familiar faces. Remember, in some cases the firesetter remains at the scene. The fire officer should have knowledge of the six firesetter motive classifications that I referenced in my previous article on in December 2010.

Fire Operations

As the fire officer you should note the location and extent of the fire and any ventilation holes or openings made. Keep in mind that ventilation plays a major role in fire spread and development. Did the fire department have to force entry or was the structure open? Look for forcible entry tools that were left behind such as pry bars or screwdrivers. If these items are found, they must be protected as evidence. Note any prior structural damage such as holes in floors, walls or ceilings. Make a mental note of any entry or egress problems that would hamper fire department operations. Remember what tactics were used for extinguishment. What was the operating mode, offensive, defensive or no attack? All of these questions should be part of the interview of the first arriving company by the fire investigator.

Overhaul Operations

For fire officers and firefighters overhaul is as important as the extinguishment of the fire. Officers need to make sure that the fire is completely extinguished to prevent a rekindle. If a rekindle occurs, it is often worse than the original fire because the structure has been compromised. Overhaul can be preformed in two phases, pre-control and post-control. Pre-control overhaul is conducted when the fire is still burning and still has control. Post-control overhaul is conducted after the fire is under control. Fire department members need to extinguish the fire before the interior examination can begin. Remember, the fire investigator may benefit from being present during overhaul operations.

Fire department personnel should make every effort to avoid any unnecessary damage during overhaul operations. The fire officer should supervise members conducting overhaul operations and ensure the investigator is aware of, and approves the removal of, any furnishings or building contents from the structure. It is the officer’s responsibility to ensure that all the contents at the area of origin are not thrown out the window or placed on the front lawn. During overhaul, areas of the fire building need to be opened to check for fire extension. However, members should use caution and know when to stop. The use of a thermal imaging camera (TIC) will assist with this task. The officer should stop firefighters from removing all the sheetrock and plaster from the studding. The reason for this is that the investigator will need to examine the fire patterns. Fire patterns are the measurable or visible effects that remain after the fire. The interpretations of fire patterns are valuable for identifying the potential ignition source. The key to successful overhaul operations is training. The fire investigator should conduct training and/or put out a memo on fire patterns and overhauling for fire investigation.

Indicators of the Incendiary Fire

The incendiary fire is defined as a fire that has been ignited deliberately in which a person knows the fire should not be ignited. The fire officer may come across the indicators of an incendiary fire during suppression operations or overhaul. The company officer should make notification to the incident commander as soon as any indicators of an incendiary fire are found. There are many incendiary fire indicators that the officer should be aware of and thus take steps to protect and preserve the evidence for the fire investigator. Let’s define some of the indicators.

Multiple Fires: Non-related fires that are burning simultaneously with different areas of origin. Fires that are on different stories of the structure at the same time, that are not connected. Fires that are located in different rooms of the structure that are not connected. I responded to a late-night fire a few years ago. Upon arrival, we had three commuter buses that were fully involved and about a half-mile away we had a storage container burning. This is an indication that you may have a set fire. The fire officer should request the investigator to respond when multiple fires are burning.

Trailers: Trailers are used to spread the fire from one area to another. They can be used on stairways to move the fire from story to story. They can be used on floors to connect fires. They can be used with a time-delay device. Time-delay devices are used to allow the firesetter to leave the scene. If trailers are found, it is strong evidence that it is an incendiary fire. Some of the materials used for trailers are paper/newspaper, clothing/rags, and ignitable liquids.

Incendiary Devices: These devices are used to initiate the incendiary or arson fire. Examples of devices are firebombs, Molotov cocktails, matchbook devices, candles in the area of origin, and balloons with ignitable liquids. If any incendiary devices are found, secure the area to protect the evidence. Moving or touching the devices can be dangerous and can result in an explosion or ignition of the device.

If the device did not activate, do not attempt to move it. This is a job for specially trained explosive ordinance disposal (EOD) personnel.

In addition to the above indicators, there is a full list in NFPA 921 Guide for Fire and Explosion Investigations to include: removal of the contents; replacement of stock or inventory; sabotage to fire protection systems; existing fire-code violations; crime concealment; or fires near service equipment or appliances. NFPA 921 will give fire officers a good foundation of the indicators of an incendiary fire.

Evidence Preservation

Fire investigators should be dispatched on the report of a working fire (but follow your department’s guidelines). Legal problems associated with evidence collection can be avoided by fire department personnel by safeguarding and preserving the evidence at the fire scene. The fire department must maintain control of the building or area until the investigator arrives and requests assistance from the police department for scene security. The fire officer should limit all access to the area of origin to members who need to be there or the member standing fire watch. Occupants and non-fire personnel should not be allowed in the structure or area until approved by the fire investigator. Fire officers need to make an effort to protect and preserve the evidence even if they have to stop their entire operation. Make sure to leave the evidence where it was found, cover it with Visqueen and tape off the area with fire-line tape. A good idea is to issue your company officers digital cameras so they can take pictures while protecting evidence.

Press Release by Fire Officers

All fires are traumatic and devastating events that invite a great deal of attention. The media will be on the scene and want to get a statement from fire department personnel, especially if the fire is a large dollar loss or if death or injury has occurred. Make sure as a company officer, you direct all questions to the Incident Commander or Public Information Officer (PIO). Be careful not to put out the wrong information. Statements like, “The fire does not appear to be suspicious at this time” should not be used. If it turns out to be an incendiary fire, you may have to explain that statement in court. Try to use statements such as, “The cause of the fire is under investigation by the fire investigation unit or fire marshal.”


The fire officer has tremendous responsibility at a working fire. There are a number of tasks that need to be completed. The identification of the indicators of the incendiary fire is one of them. Remember, rapid extinguishment of the fire protects and preserves evidence. Fire officers should keep alert and protect any evidence found on the scene. If the investigator is not dispatched on the report of a working fire, contact the fire investigator as soon as you start overhaul operations or start to find any indicators of an incendiary fire. Remember, if you find a device that has not activated, do not touch it — call the EOD. Contact your local fire investigator and ask questions about fire investigations. I’m sure the investigator will have no problem with setting up an awareness-level training for your department.


ROBERT DISBROW JR. is a 21-year veteran of the fire service. He is a career firefighter/investigator with the City Of Bayonne, NJ, Fire Department and also conducts origin and cause investigations for a forensic engineering firm based in New Jersey. He is a life member of the Laurelton Fire Co. # 1 and a fire commissioner for the Howell Township Fire District # 1. He holds an associate degree in fire science and is a certified fire and explosion investigator (CFEI). He is also certified as a fire inspector, hazardous material specialist, fire instructor and juvenile firesetter intervention specialist and has been investigating fires for the past 15 years. He can be reached via e-mail at: [email protected].

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