Continuing Education
References:
HFD Arson Division
HFD Rules and Regulations
Investigating the Fireground - Phillips, McFadden
NFPA 921 Guide for Fire and Explosion Investigations
Essentials of Fire Fighting - IFSTA
Texas Commission on Fire Protection
Fireworld.net
Public Adjusters USA
Introduction
Fire cause determination is the process of investigating the circumstances and conditions that bring the fuel, the ignition source and an oxidizer together, resulting in a fire or combustion explosion. A systematic approach with attention to all relevant details by the firefighting crews and the investigator will help uncover new data that might have been otherwise overlooked. Before one can investigate the cause, the origin must be determined and established. To establish the origin, the fire scene must be disturbed as little as possible.
In the Houston Fire Department, the commanding officer of the scene is responsible for attempting to determine the cause of fire and to substantiate any determination with facts. When impossible to determine an accidental cause or, when impossible to substantiate a suspected cause of fire with facts, the officer in charge shall call for an Arson Investigator. When requesting an investigator, the dispatcher will need to be advised of a few items. He/she will need to know if the structure is occupied or unoccupied. If a suspect is being detained at the scene, advise the dispatcher of their gender and age (adult, juvenile or child). This will determine the number of investigators that will be sent to the location and will expedite the process.
After an investigator is called for, all firefighting activity should be stopped once the main body of fire is knocked down and the area is made tenable for crews. The scene is now a crime scene! Any future firefighting activity should be on an emergency basis or after the investigators have released the scene back to the fire ground commander.
A thorough analysis of the scene will indicate the area(s) where the fire originated and the cause of the fire. Below is a list of the most common reasons for setting arson fires.
Vandalism* 55%
Revenge 12%
Conceal other crimes 7%
Pyromaniacs 3%
Arson for profit 2%
Other 15%
*The FBI's National Center for Analysis of Violence in Crime has also found that juveniles cause 96% of all vandalism arson fires.
The Firefighters Role
The role of suppression firefighters in fire cause determination is a crucial link in the investigation. Without the information from the firefighting crews, the job of the investigator would be much harder. There are four main areas of responsibility for suppression firefighters in aiding the investigator performing fire cause determination.
The four main areas are:
1. Observations
2. Fire extinguishment
3. Evidence and scene preservation
4. Documentation of the scene
Observations
Observations made while enroute to the emergency might include noting the time of day or night. At 3a.m., one should expect people in a family dwelling to be in bed and wearing sleeping apparel. An office building, at that same time, should be empty except for security and cleaning personnel. This might not always be the case with our constantly evolving 24-hour society, but is still an odd occurrence to have office employees present at such an unusual hour. An open window during extreme hot and cold weather conditions may be normal for the building but it should at least merit a closer investigation.
Other observations while enroute might include natural and man-made barriers. Tree branches and construction barriers might be placed in the path of the responding apparatus to allow the fire time to intensify. A stalled out vehicle might be more than coincidence. Making a mental impression of these items is important.
People are naturally curious and they will flock toward the scene of an emergency. Vehicles and people that are observed leaving in a hurry from the vicinity of a fire should be noted. Providing the investigator with a description of the vehicle and the individual's personal appearance might be a valuable piece of information. If the instinct is strong, this information may be passed on immediately to the dispatcher. People that are observed, on a reoccurring basis at different fire scenes would also warrant close investigation. The apparatus engineer is a valuable set of eyes during scene operations.
Once on location, a scene size-up is conducted and a lot of information is processed and analyzed in order to make the initial fire attack. Observations made from the exterior of the building may fall into three groups: First are the characteristics of the visible smoke and fire. Second would be observations of the structure itself. Third would be the people
and /or the surrounding activity.
Characteristics of the flame should include, but are not limited to, the location(s), color, and intensity. Problems encountered while attempting to extinguish the fire should also be noted and reported. Observations of the smoke might include color, density, location(s) and even smell. These factors may indicate how long the fire may have been burning, the fire's intensity, the type of materials burning, and the possible area of origin.
Upon attempting to enter the structure, the first in crew should make a mental note of any forced entry damage made prior to arrival. Locked or unlocked doors and windows and any doors that are covered should be noted and reported. Once inside the structure, any obstacles that might impede firefighter access should be passed on to the incident commander immediately. Any forced entry and the method used by fire fighters must be reported to the fire ground commander and the arriving investigator.
As a safety precaution, firefighters normally shut off the electrical power to a structure. The shutting-off of any utilities should also be reported to the incident commander and the investigator. The person shutting off the electrical service should make a mental note as to which, if any, breakers were in the "tripped" position when he/she cut the power off. Any abnormalities in or around the breaker box also need to be reported to the incident commander and the investigator. It must also be noted if the gas service to the structure was off or on at the time of the fire.
At the scene of a vehicle fire, observe the surroundings as you approach the scene. Is there any vehicle leaving the area? What about bystanders or wreckers? Be observant for possible items of evidence. An arsonist may have used a different container for flammable liquid storage.
Fire Extinguishment
Prompt control and extinguishment of the fire aids in the protection of evidence. A conservative use of water during extinguishment will also aid in the investigation of the scene and any use of water for overhaul must be prohibited until the investigation is complete or until the investigator gives the "OK". During extinguishment efforts, firefighters need to make mental notes of things they saw, heard, or smelled during that phase of operation. These mental notes must be reported to the incident commander and/or the investigator because they may aid in the investigation of the fire scene.
Do not leave hose lines in the building while waiting for the investigator to arrive. Most hose lines leak water and will damage or destroy evidence. If the incident commander is concerned of a rekindle while waiting for the investigator, the line should be backed out of the building with the nozzle placed at the outside doorstep, charged and ready to move into the structure. Looking for hot spots is considered overhauling and is not to be done until the investigator is finished with a thorough examination of the fire ground.
Fire Ground Scene Preservation
The ability to preserve the fire scene is always an important element in the investigation of a suspected incendiary fire. All steps necessary, up to and including posting of a firefighter at the entrance, must be taken to preserve the scene. Barrier tape is a cheap and effective way to keep out unwanted onlookers, occupants and news media personnel. If the scene is a residence, the surrounding yard may have to be taped off. If the scene is not taped off, you might ask the investigator when he arrives if it needs to be taped off. Once an investigator is called for, the scene becomes a crime scene until proven otherwise and any assistance give to the investigator, such as taping the scene, would be greatly appreciated. It should also be remembered, that once an investigator is called for, all unnecessary firefighting personnel should be removed from the immediate area to avoid destroying any possible evidence. Property owners and members of the media should not be permitted into the structure under any circumstances until the investigator requests their input or has released the scene.
Once an item has been found and determined to be a possible piece of evidence, all steps necessary must be taken to preserve and protect the item, in place, as much as possible, from loss, further destruction or movement. The person making the discovery should notify the incident commander as soon as possible. In some instances in the past, items have been handled out of curiosity. This may put a question in the minds of a jury as to the control of evidence. Pulling ceilings and walls should be avoided, if at all possible, until the investigator has completed their investigation of the scene. The movement of hose lines and the use of straight streams can move, damage, or destroy physical evidence that may be present.
Vehicle Fires
At a vehicle fire scene, look for evidence of containers, trailers or other items of question. Check the VIN plate of the vehicle.
A HPD wrecker must be called any time that the complete VIN cannot be read at a
suspected arson fire. HPD will make the determination of ownership at all
vehicle fires. The vehicle must be towed by an HPD wrecker to the impound lot on Dart street. A license plate being present with the vehicle doesn't mean any wrecker can haul it. Some thieves will steal a tag from another vehicle that is the same make and model to help cover their tracks. Do not assume it is correct unless the VIN and license plate are clearly legible and matched by HPD. Document what is found and/or tampered with on the vehicle. Any damage done to the vehicle during firefighting activities must be reported to the investigator.
Evidence
There are three types of evidence: testimonial, documentary and physical. Evidence is comprised of the indicators collected by the fire investigator that constitute the basis for his/her opinion with regard to the causation of the fire and that may be presented in a court of law to establish the facts supporting those opinions. If evidence is not collected, documented, properly handled and preserved, it may lose its credibility and be declared inadmissible by a judge. This could mean the difference between winning and losing a conviction.
Physical evidence may range from containers that may have held flammable/combustible liquids to sophisticated timing mechanisms. It is to the benefit of firefighters as well as investigators to protect evidence of arson by leaving it untouched. By touching or moving evidence, firefighters can destroy its credibility.
Documentation
Unfortunately, there is an increasing trend in persons pursing legal action against public entities. The fire service, which once enjoyed virtually no legal suits, is no longer immune to criminal or civil action. This has become evident in Houston in recent years. Proper documentation of the scene, by the commanding officer, is of paramount concern. Including all information that pertains to the response and the fire ground activity in the fire report is not only necessary but also legally required. Passing along all of this information to the investigator is an essential part of the investigation of the scene. Even the most minute piece of information may be important. Give the information to the investigator and let him/her decide if it is important. He/she is the one trained in the investigative process and is ultimately responsible for the scene investigation.
Summary
To establish the origin of a fire, the fire scene must be preserved and protected. Using water conservatively and limiting wall and ceiling opening will help maintain evidence in its original state. Careful observation and thorough documentation of the fire scene will help support the arson investigator's findings. Keep the crime scene safe and secure by using barrier tape to maintain a perimeter.
