The investigation of even the most blatant arson incident likely will be subjected to intense review and scrutiny and, ultimately, be defended in a criminal or civil courtroom. A legal team preparing for such a defense likely will look for the weakest details upon which the arson finding is based. Oftentimes, that comes down to just how secure a building was prior to the fire and if someone other than the accused had sufficient access to commit the crime. Fire investigators can avoid overlooking or being complacent about this very critical aspect of investigating an arson incident by following a methodology to adequately investigate the pre-fire premises security.
Often, fire investigators become so consumed with the causation aspect of the fire scene investigation that the opportunity assessment is not fully investigated and properly documented. When a building is set on fire intentionally, being able to “lock the doors and close the windows” will substantially allow for narrowing the list of potential perpetrators.
An interview with the homeowner, building occupant, or the person who manages a commercial building should be conducted soon after a fire occurs to establish whether or not the premises were locked and, if so, how many keys there were and who has those keys. It also should address any remote controls for garage doors and who may have had access codes to activate any exterior keypads that can be used for entry, and it should determine whether or not there was any pre-existing, forced-entry damage.
Additionally, interviews should be conducted with the responding fire officials and any discovering witnesses who may be able to offer information about the status of doors and windows at the time the fire was discovered. Firefighters can provide important information about alterations made to doors and windows during the fire suppression efforts, including any manipulation of locking mechanisms.
As with the origin and cause investigation, the premises security investigation begins at the exterior. The fire investigator should identify all means of entrance into a building. Each door and window should be identified on a diagram as the fire investigator assesses the condition of each. Depending on the degree of fire damage, the pre-fire condition of some may be easily established. Others may require further study.
All entrance doors should be carefully examined. These include casement doors, sliding glass doors, patio screen doors, and garage doors. The locking mechanisms for each should be evaluated and documented with photographs. This includes the lock itself, the strike plate, and the casing mortise that receives the lock bolt. Any evidence of forcible entry should be noted and properly documented. Since it often is required that firefighters make forcible entry into a burning building, subsequent interviews with the first arriving firefighters are essential to establish whether the forcible entry was done prior to their arrival or as a part of the fire suppression efforts.
In instances when the fire damage is great, it still is possible to determine the security status of a door by examining the lock that may be in the fire debris. The hinges should be examined as well because it may yield evidence to show whether a door was open or closed when a fire occurred. Additionally, burn patterns on floors can sometimes show a line of demarcation if a door was open during a fire. Doors containing glass panes should be examined to see if the pane was broken prior to the fire.
Sliding glass doors often are secured with the use of a rigid board or stick that is placed in the inside track to prevent the door from sliding open. The fire investigator should look for this and document whether or not one is present. Smoke-staining on the door frame can sometimes be used to establish whether or not a sliding glass door was open when a fire occurred. Garage door security usually can be established by examining the locking mechanism or the door opener mechanism, if there is one present. Burn patterns on metal garage doors often reveal the position of that door during the fire.
Each window must be examined to establish whether it was open or closed when the fire occurred and whether or not it was locked. While this may be easy for some fire incidents when the frame and glass are intact, it can be more difficult if the window glass fails during a fire or is broken by firefighters to allow for ventilation.
To evaluate the security status of a window with broken glass, a study of the smoke-staining on the glass is required. Broken glass pieces found on the floor near a window with smoke staining on the bottom side is an indicator that the window glass was in place as the fire occurred. Layering debris near a window is an important process when window glass has been broken out. Window-glass fragments found underneath fire debris indicates that the window was broken prior to or early in the fire and were on the floor as fire debris fell and collected atop them. An examination of the sides of broken glass fragments will show conchoidal stress cracks that radiate from the side of impact if broken by force. These cracks will not be present on glass that is broken from fire.
Smoke-stain patterns on window frames should be examined and documented as it often can show the status of the window frame at the time of a fire. Just as a protected space on a floor is a tool used by fire investigators to reconstruct a fire scene, the same is true for window frames that have not sustained heavy fire damage. A partially open window may leave protected areas of the window frame that can be used to show the position of the window when a fire occurred. This is important because the position of a window may have been altered by firefighters to allow for cross-ventilation, and a reconstruction must be done.
Other considerations when evaluating a window as a means of access include to what extent it offers ease of entry. A window that is eight feet above the ground would require a ladder or some similar means to allow someone to enter through it. As such, most second-floor windows or windows built on houses above grade-level usually can be excluded as a means of entry. Also, if the placement of furnishings in the interior obstructs entry through a window, it should be evaluated and recorded.
Window screens and screen frames also should be evaluated. If these are found to have been in place when a fire occurred, then it usually is evidence that the window was not used as a means of entry or exit. Additionally, sooting lines of demarcation may be evident on window screens to establish if windows were open during a fire.
Alarm systems and surveillance cameras also should be considered and investigated, especially for commercial fire losses. Knowing what type of alarm system is present and reviewing what records the alarm monitoring company can provide will assist in establishing pre-fire premises security. The same is true of any surveillance camera footage that is often found in commercial and residential occupancies. For commercial loss sites, any exterior fencing should be examined closely for security and documented accordingly.
While NFPA 921 does not offer much guidance for the investigation of pre-fire premises security, an investigator who follows these recommendations will conduct a much better objective investigation that should withstand even the harshest cross-examination.
As a claims professional, a pre-fire premises security investigation should be considered essential, as the decision to deny an arson claim can come down to how secure the building was when the fire occurred.