Chapter 17

Protecting Evidence for Fire Cause Determination

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Chapter 17

Protecting Evidence for Fire Cause Determination INTRODUCTION [NFPA 1001: 4-3.4; 4-3.4(a); 4-3.4(b)]

Fire departments should investigate all fires to determine the cause of the fire (Figure 17.1). The cause of a fire is a combination of three factors: •

Fuel that ignited

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Form and source of the heat of ignition

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Act or omission that helped to bring these two factors together

Knowing the cause of fires helps prevent fires in the future. Reduced fire loss means that the public is getting the protection that it expects and that the fire department is fulfilling its obligation to provide that protection. As fire incidents decrease, so do loss of life and adverse economic impact. The firefighter on the scene has the best opportunities to observe evidence of cause and to assist in the fire cause determination effort. The firefighter is an important link in the chain for determining how a fire started and why it spread as it did. It is the responsibility of the fire department to respond and extinguish a fire as quickly as possible. However, the results of the fire fighting operation may impair an investigator in conducting a fire origin and cause determination investigation. The firefighters’ actions may move evidence from its original location or completely sweep it away (Figure 17.2). It is extremely important that firefighters take precautions in protecting evidence while fighting a fire.

Figure 17.1 As a result of thorough fire investigations, investigators can identify and explain the origin and cause of the fire and who or what was responsible. Courtesy of Scott L. Davidson.

In order to properly analyze fire cause, it is necessary for firefighters to protect evidence at the scene. A fire officer, fire investigator, or firefighter trained in collecting and preserving evidence collects and analyzes the evidence to determine the exact cause.

Information gathered at the scene is of critical importance to the fire investigator. Investigators are seldom present while firefighters fight a fire, perform overhaul, and interview occupants and witnesses to obtain information. Legal proceedings concerning a particular fire may also become necessary. For these reasons, firefighters must be responsible for noting everything that could point to the origin and cause of a fire. This chapter contains information on the responsibilities of the firefighter and the fire investigator. Observations that the firefighter can make en route, upon arrival, and during and after the fire which could assist in a subsequent fire

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ESSENTIALS and collect important information by observing the fire and its behavior during the response, upon arrival, when entering the structure, and while locating and extinguishing the fire. More than anyone else, the firefighter is aware of unusual conditions that may indicate an incendiary (arson) fire. The first-arriving firefighters may be able to best answer some important questions such as the following: •

Are the contents of the rooms as they normally would be? Are the rooms either ransacked or unusually bare?

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Are the doors and windows locked or open? Is there evidence of forced entry prior to the arrival of firefighters?

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Are there indications of unusual fire behavior or more than one area of origin?

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Are vehicles or people present in the area?

Firefighters must be aware during fireground operations that what they do and how they do it can affect the determination of the origin and cause of the fire. Having an alert and open mind combined with performing judicious and careful overhaul might also uncover important evidence that would otherwise be lost. ROLE OF THE INVESTIGATOR Figure 17.2 Overhauled materials are often piled outside the structure.

investigation are also covered. The chapter also discusses steps for securing the fire scene and protecting evidence. Finally, the chapter covers the firefighter’s conduct at the scene and legal considerations. For more information, refer to IFSTA’s Introduction to Fire Origin and Cause manual. RESPONSIBILITIES OF THE FIREFIGHTER [NFPA 1001: 4-3.4(a)]

The fire chief has the legal responsibility within most jurisdictions for determining the cause of a fire. The fire chief relies on the fire officers and firefighters at the scene to make sure that the true and specific cause of the fire can be determined. Proper training enables firefighters to recognize

[NFPA 1001: 4-3.4(a)]

Fire marshals, fire inspectors, or other members of a fire prevention bureau are usually responsible for carrying fire cause investigations beyond the level of the fire company (Figure 17.3). Firefighters may be questioned by an investigator or asked to assist in some aspect of an investigation. Some fire departments have special fire investigation or arson squads. In other departments, fire department and law enforcement personnel work together. There are also localities where the police department has sole responsibility for handling an investigation. In other areas, the responsibility for cause determination and investigation lies with the state fire marshal or some other state agency rather than with local agencies. Private companies may con-

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•

Time of day — Are people and circumstances at the scene as they normally would be this time of day? For example, if a fire is in a dwelling at 3 a.m., the building occupants would probably be wearing night clothes, not work clothes. If a fire is in an office building after working hours, the owner or employees should have a valid reason for being present at that hour.

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Weather and natural hazards — Is it hot, cold, or stormy? Is there heavy snow, ice, high water, or fog? If the outside temperature is high, the furnace in the structure would not be operating. If the outside temperature is low, the windows normally should not be wide open. Arsonists sometimes set fires during inclement weather because the fire department’s response time may be longer.

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Man-made barriers — Are there any barriers such as barricades, fallen trees, cables, trash containers, or vehicles blocking access to hydrants, sprinkler and standpipe connections, streets, and driveways? These situations could indicate an attempt on someone’s part to delay fire fighting efforts (Figure 17.4).

Figure 17.3 A fire investigator is responsible for conducting, coordinating, and completing a fire investigation. Courtesy of Ron Jeffers.

duct separate investigations when a fire involves their property, or the investigation may be conducted by an insurance company. OBSERVATIONS OF THE EMERGENCY RESPONDERS [NFPA 1001: 3-3.7; 3-3.7(a); 3-3.7(b); 3-3.12(a); 33.12(b); 4-3.4(a); 4-3.4(b)]

Some of the observations that firefighters make and some of the actions that firefighters perform may be done at different times throughout an incident. For example, firefighters may not find evidence of unusual fire behavior until performing overhaul. A thorough search for containers and signs of forcible entry may not be feasible until the fire is extinguished. The important point is not when the firefighter notices something that can lead to the cause but that the firefighter takes the proper steps afterwards. Observations En Route The firefighters’ responsibility for gathering information begins when the alarm is received. The firefighter should gather information on the following factors:

Figure 17.4 Man-made barriers are sometimes used to delay the fire department’s response to an emergency.

•

People leaving the scene — Are people leaving the scene? Most people are intrigued by a fire and stay to watch (Figure 17.5). On the other hand, people leaving the scene by vehicle or on foot may be suspicious. Therefore, when a person leaves the scene by vehicle, make note of the color of the vehicle, its approximate year, its model, the

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ESSENTIALS frames (Figure 17.6). Sometimes doors and windows are covered with blankets, paint, and paper to delay discovery of the fire. •

Location of the fire — Determine the location of the fire. This information helps to identify the area of origin. Also note whether there were separate, seemingly unconnected fires. If so, the fire might have been set in several locations or spread by trailers (combustible material used to spread fire from one area to another).

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Containers or cans — Note metal cans or plastic containers found inside or outside the structure. They may have been used to transport accelerants.

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Burglary tools — Note tools such as pry bars and screwdrivers found in unusual areas. They may have been used by a person to enter the facility to set the fire (Figure 17.7).

Figure 17.5 Observe bystanders at the scene. Note if the same person seems to be present at several fires.

body style and condition, and the license plate number. Notice if any occupants are in the vehicle. If a person leaves the scene on foot, note the person’s attire, general physical appearance, and any peculiarities such as someone trying to leave undetected, walking briskly, or looking over his shoulder. Observations Upon Arrival Additional information that firefighters should gather upon arrival at the scene may include the following: •

Time of arrival and extent of fire — Ask the person who reported the fire or other witnesses about the extent of the fire at the time it was discovered and reported. The person who reported the fire can be questioned thoroughly at a later time. Note the locations of smoke columns and flames and determine whether flashover or self-ventilation occurred. If the fire self-ventilated, was it vertical or horizontal?

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Wind direction and velocity — Note wind direction and velocity. These factors may have a great effect on the natural path of fire spread.

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Doors or windows locked or unlocked — Note the position and condition of doors and windows upon arrival. Before opening doors and windows, determine whether they are locked, are unlocked, or show any signs of forcible entry such as broken glass or split

Figure 17.6 Check for signs that forcible entry was made before fire department personnel arrival.

Figure 17.7 Look for forcible entry tools that may have been used to enter the facility.

Protecting Evidence for Fire Cause Determination •

Familiar faces — Look for familiar faces in the crowd of bystanders. They may be fire buffs, or they may be habitual firesetters.

•

Incendiary devices — Note pieces of glass, fragments of bottles or containers, and metal parts of electrical or mechanical devices. Most incendiary devices (any device designed and used to start a fire) leave evidence of their existence (Figure 17.9). More than one device may be found, and sometimes a faulty functioning device can be found during a thorough search.

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Trailer — Note combustible materials such as rolled rags, blankets, newspapers, or ignitable liquid (trailer) that could be used to spread fire from one point to another. Trailers usually leave char or burn patterns and may be used with incendiary ignition devices (Figure 17.10).

Observations During Fire Fighting Firefighters should continue to observe the following conditions that may lead to the determination of the fire cause: •

Unusual odors — Note unusual odors. Firefighters should always wear self-contained breathing apparatus (SCBA) during fire suppression and overhaul operations. However, unusual odors may sometimes be detected at the fire scene.

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Abnormal behavior of fire when water is applied — Observe fire behavior when applying water on a fire. Flashbacks, reignition, several rekindles in the same area, and an increase in the intensity of the fire indicate possible accelerant use. Water applied to a burning liquid accelerant may cause it to splatter, allowing flame intensity to increase and the fire to spread in several directions. Water applied to fires involving ordinary combustibles usually reduces flame propagation.

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Obstacles hindering fire fighting — Note whether doors are tied shut or furniture is placed in doorways and hallways to hinder fire fighting efforts (Figure 17.8). Holes may be cut in the floors that not only hinder fire suppression activities but also spread the fire.

Figure 17.8 Furniture may be placed in front of doors to block the firefighter’s entry.

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Figure 17.9 Most incendiary devices leave evidence of their existence.

Figure 17.10 A trailer is used to spread fire from one point to another. Courtesy of Elk Grove Village (IL) Fire Department.

626 •

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ESSENTIALS Structural alterations — Observe alterations to the structure: removal of plaster or drywall to expose wood; holes made in ceilings, walls, and floors; and fire doors secured in an open position (Figure 17.11). All of these methods are designed to abnormally spread or move fire quickly through the structure. Fire patterns — Note the fire’s movement and intensity patterns. These can trace how the fire spread, identify the original ignition source, and determine the fuel(s) involved. Carefully note areas of irregular burning or locally heavy charring in areas of little fuel.

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Heat intensity — Look for evidence of high heat intensity, especially in relation to other areas of the same room. This may indicate the use of accelerants. However, other factors may contribute to variations in heat intensity. One of these factors is synthetic materials, such as polyurethane, that may produce areas of normal high heat intensity and may be confused with the use of accelerants.

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Availability of documents — Be alert to the sudden production of insurance papers, inventory lists, deeds, or other legal documents that may indicate that the fire was premeditated.

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Fire detection and protection systems — Check for evidence of tampering or inten-

Figure 17.11 Fire spreads more quickly throughout a structure when a hole has been chopped in the floor.

tional damage if fire detection and protection systems and devices are inoperable (Figure 17.12). •

Intrusion alarms — Check intrusion alarms to see whether they have been tampered with or intentionally disabled.

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Location of fire — Note ignition sources or possible ignition sources in the area of the fire. Fires in areas remote from normal ignition sources may indicate suspicious activity. Some examples are fires in closets, bathtubs, file drawers, or in the center of the floor.

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Personal possessions — Look for the following indicators that preparations were made for a fire: absence or shortage of clothing, furnishings, appliances, food, and dishes; absence of personal possessions such as diplomas, financial papers, and toys; absence of items of sentimental value such as photo albums, special collections, wedding pictures, and heirlooms; absence of pets that would ordinarily be in the structure (Figure 17.13). (NOTE: Do not read too much into a lack of material possessions. A person’s economic status may dictate his lifestyle, and some people just do not have as much as others.)

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Household items — Note whether major household items appear to be removed or replaced with junk. Other items may also

Figure 17.12 A smoke detector may be disabled to delay the detection of the fire.

Figure 17.13 Missing personal possessions, such as clothes, may indicate that preparations were made for a fire.

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appear to be replaced with items of inferior quality. Check to see whether major appliances were disconnected or unplugged and determine why they were in this condition. •

Equipment or inventory — Look for obsolete equipment or inventory, fixtures, display cases, equipment, and raw materials.

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Business records — Determine if important business records are out of their normal places and left where they would be endangered by fire. Check safes, fire-resistant files, etc., to determine whether they are open and exposing the contents.

Responsibilities After the Fire Firefighters should report all facts concerning the fire to the officer in charge as soon as possible. Each firefighter should write a chronological account of important circumstances personally observed. A written account will be valuable if the firefighter must testify in court later. Cases often come to trial several years after an incident, and a person should not rely on memory alone. Report hearsay to the investigator for validation. Example: “The neighbor told me that he saw the lights flickering for a few days before the fire.” This is hearsay, but it may be very helpful to the investigator.

Figure 17.14 Evidence may be found in debris that has been thrown outside.

CONDUCT AND STATEMENTS AT THE SCENE [NFPA 4-3.4(a)]

Although firefighters and the fire officer should obtain all information possible pertaining to a fire, they should not attempt to interrogate a potential arson suspect. The moment one suspects a particular person of arson, he should call a trained investigator to conduct an interview. It is the trained investigator’s job to interview an arson suspect. Allow the owners or occupants of the property to talk freely if they are inclined to do so, and give them a sympathetic ear. Some valuable information is often gathered this way.

Salvage and overhaul are probably the pivotal operations in determining fire cause. Some departments take great pride in their salvage and overhaul work and boast that they leave a building neater, cleaner, and more orderly than it was before the fire. This thoroughness in salvage and overhaul is admirable, but in many cases it destroys evidence of how a fire started. Delay thorough salvage and overhaul work until the area of origin and cause have been determined.

Fire personnel should never make statements of accusation, personal opinion, or probable cause to anyone. These opinions easily could be overheard by the property owner, news media, or other bystanders who could consider such statements fact. Careless joking and unauthorized or premature remarks that are published or broadcast can be very embarrassing to the fire department. Many times these remarks impede the efforts of an investigator to prove malicious intent as the fire cause. A sufficient reply to any question concerning cause is “The fire is under investigation.”

Fire personnel should perform salvage and overhaul carefully. They should not move more debris than is necessary, especially in the area of origin, because it may hamper the investigation. Neither should firefighters throw debris outside into a pile — evidence is buried this way and may be permanently lost (Figure 17.14).

After the investigator arrives, personnel should make their statements only to this individual. Any public statement regarding the fire cause should be made only after the investigator and ranking fire officer have agreed to its accuracy and validity and have given permission for it to be released.

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ESSENTIALS

SECURING THE FIRE SCENE [NFPA 4-3.4(a); 4-3.4(b); 3-3.13(b)]

The most efficient and complete efforts to determine the cause of a fire are wasted unless the building and premises are properly secured and guarded until an investigator has finished evaluating the evidence exactly as it appears at the scene. Firefighters should take care not to contaminate the scene while operating power tools, hoselines, or other equipment. If an investigator is not immediately available, the premises should be guarded and kept under the control of the fire department until all evidence has been collected (Figure 17.15). All evidence should be marked, tagged, and photographed at this time because in many instances a search warrant or written consent to search will be needed for further visits to the premises. This duty might be given to law enforcement personnel, depending on local policies and personnel availability, but whenever possible it should be carried out by fire department personnel trained in evidence collection and preservation.

Fire personnel should not allow anyone to enter a fire scene without the investigator’s permission, and an authorized individual should escort the subject. During fireground operations and the investigation, make a recorded log of any such entry. The log should show the person’s name, the time of entry, the time of departure, and a description of any items the person took from the scene. The premises can be secured and protected in several ways with the use of few personnel. Areas that are fenced can be monitored by one person at a locked gate. At large fire scenes, a full-time guard force is often employed to handle the situation. In some extreme instances, all doors, windows, or other entrances could be completely closed with plywood or similar material. Cordoning off the area also can help provide a safe and secure fire scene. With the area cordoned, bystanders are kept at a safe distance from the incident and out of the way of emergency personnel. There are no specific boundaries for the cordon. Cordoning can be accomplished with rope or specially designed fire and police line tape. It may be attached to signs, utility poles, parking meters, vehicles, or any other objects readily available. Once in place, law enforcement personnel should monitor the line to make sure people do not cross it. Be aware of seemingly innocent persons (including curious people and the press) attempting to cross a line. Escort from the area anyone in the cordoned area who is not a part of the operation. Record any information obtained from them for future reference. LEGAL CONSIDERATIONS

Figure 17.15 Cordon off the scene with fire line tape, and secure the area with law enforcement personnel.

The fire department has the authority to bar access to any building during fire fighting operations and for a reasonable length of time after fire suppression is terminated. Fire department authority ends when the last fire department representative leaves the scene. Further visits to the scene require either the owner’s written permission or a search warrant. Fire personnel should be aware of any local laws pertaining to the right of access by owners or occupants.

[NFPA: 4-3.4(a)]

As previously stated, firefighters may remain on the location as long as necessary, but once they leave they may be required to get a search warrant to reenter the scene. This is based on the case of Michigan vs. Tyler (436 U.S. 499, 56 L.Ed. 2d 486 [1978]). The U.S. Supreme Court held in that case that “once in a building [to extinguish a fire], firefighters may seize [without a warrant] evidence of arson that is in plain view . . . [and] officials need no warrant to remain in a building for a reasonable time to investigate the cause of a blaze after it has been extinguished.”

Protecting Evidence for Fire Cause Determination The Court agreed, with modification, with the Michigan State Supreme Court’s statement that “[if] there has been a fire, the blaze extinguished and the firefighters have left the premises, a warrant is required to re-enter and search the premises, unless there is consent . . . .” The impact of these decisions seems to be that if there is incendiary evidence, the fire department should leave at least one person on the premises until an investigator arrives. To leave the premises, return later without a search warrant, and make a search might be enough to make prosecution impossible or for an appellate court to overturn a conviction (Figure 17.16). Each department should learn the legal opinions that affect its jurisdiction in this regard. These opinions or interpretations can be obtained from such persons as the district attorney or state attorney general. The fire department should write a standard operating procedure around these opinions.

Figure 17.16 Fire department personnel and the investigator should know the jurisdiction’s legal requirements concerning reentry of a fire scene. Courtesy of Joseph J. Marino.

PROTECTING AND PRESERVING EVIDENCE [NFPA 1001: 3-3.13(b); 4-3.4(a); 4-3.4(b)]

Firefighters should protect evidence, untouched and undisturbed if at all possible, when it is found and provide security for the area until an investigator arrives. They should not gather or handle evidence unless it is absolutely necessary in order

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to preserve it. If a firefighter handles or procures evidence, he then becomes a link in the chain of custody for that evidence. The firefighter should accurately document all actions as soon as possible. It may be necessary for this individual to subsequently appear in court. Because the amount of time involved in a court trial can be extensive, most departments do not want operational personnel to gather evidence. No changes of any kind should be permitted in the evidence other than those absolutely necessary in the extinguishment of the fire. Firefighters should avoid trampling over possible evidence and obliterating it. The same precaution applied to the excessive use of water may help avoid similar unsatisfactory results. Human footprints and tire marks must be protected. Boxes placed over prints prevent dust from blowing over otherwise clear prints and keep them in good condition for either photographs or plaster casts at a later time (Figure 17.17). Completely or partially burned papers found in a furnace, stove, or fireplace should be protected by immediately closing dampers and other openings. Leave charred documents found in containers such as wastebaskets, small file cabinets, Figure 17.17 Footprints may be and binders that can be covered with a box until they are photographed or plaster casts moved easily. Keep made. these items away from drafts. After evidence has been properly collected by an investigator, debris may be removed. Charred materials should be removed to prevent the possibility of rekindle and to help reduce smoke damage. Any unburned materials should be separated from the debris and cleaned. Debris may be shoveled into large containers, such as buckets or tubs, to reduce the number of trips back and forth to the fire area. It causes poor public relations to dump debris onto streets and sidewalks or to damage costly shrubbery. Rather, dump the debris in a backyard or alley that is not as visible.