Kiera Biggins looks at how a fire investigator can establish if a fire has been caused by an arson attack.
Fire investigation is a complex task that involves the compilation and analysis of factual data to determine the origin and most likely cause of a fire. This process is underpinned by the principles of the Scientific Method – a method developed to ensure systematic and objective analysis of facts through development, testing, and modification of various hypotheses.
As such, a Fire Investigator must remain open to considering all the potential causes, including those of arson, when investigating any fire or explosion incident they attend.
What is arson?
The exact wording of the definition of arson can vary depending on the source, but in general arson is typically considered to be the criminal act of deliberately destroying or damaging property by fire. It is a common misconception that arson relates solely to the damaging of the property of others and not personal property. However, the Criminal Damage Act 1971 also considers damage to property belonging to the offender, an act of arson. This is most commonly seen when dealing with incidents that relate to insurance fraud.
The criminal act of arson is divided into three elements. The first is the burning of property, which must be shown as actual destruction at least in part and not just scorching. The second is that the fire is incendiary in origin; for this proof must be established either through specific forensic evidence or expert testimony that all possible natural or accidental causes have been considered and eliminated. The third is that the fire is proved to be started with malice. Malice is a legal term which relates to the intention to cause harm or at least foresight that harm may result. Malice can be the most difficult to prove, in particular for criminal cases as issues with mental health, drugs, and alcohol consumption can be contributing factors which may affect intent.
It is noted that this definition relates to the classification of arson for the criminal court and that all three elements must be present for such a charge to be brought. This would also indicate that the deliberate setting of a fire for the purposes of financial benefit through an insurance claim, is insurance fraud. This means that these two crimes generally work in conjunction with each other and are treated as deliberate acts with regard to investigation purposes.
When investigating deliberate acts of fire setting there are a number of key indicators which can be used to indicate possible arson or fraudulent activity. These can be separated into property, combustion, and circumstance-related factors.
Property factors
Consider signs of forced entry
Investigators typically work from the exterior to the interior when investigating a fire, and as such some of the first key indicators an investigator will observe relate to the property. Factors investigators may look for around the exterior of a property are signs of forced entry such as broken windows, damage to door locks and frames, or windows that have been left open contrary to weather conditions. Evidence of unauthorised or forced entry is a positive indicator that someone may have entered the incident property for the purposes of starting a fire or to commit other crimes and then attempt to destroy evidence with fire.
Although these may be indicators of deliberate entry into a property, care must be taken to confirm this as they may also be caused by firefighting and post-fire ventilation actions. Interviews with fire crews should take place to determine what actions they or members of the public have taken to gain access. The use of Crime Scene Investigators may also be beneficial because of their skills in recognising and recording evidence of damage such as tool marks.
Care must also be taken to consider whether the signs of forced entry are staged, for example, mechanically broken windows with the glass located on the exterior rather than the interior of the property. This is a sign that the glass has been smashed from the inside rather than the outside. Other indicators may be the presence or lack of soot staining to the glass observed. Thermally damaged glass will typically (but not always) be smoke stained, and its fractures will be smooth, wavy and at the edges near to the frame initially. Impact broken glass may well be clean and have conchoidal (smooth curved) fractures on the edges.
Obtain and review CCTV footage
Another key information source when dealing with the property is the presence of CCTV cameras, security, and fire alarms. CCTV footage can be critical when investigating arson incidents. One of the main issues with obtaining CCTV in the event of a fire is that the equipment can become damaged deliberately or through the natural course of fire spread. In these instances, the gathering of CCTV evidence should not be limited to the specific property or the street it is on. Footage from neighbouring properties, neighbouring streets, and/or alleyways, council cameras, and local stores has and can successfully be used to show the presence of individuals and/or vehicles around the location of an incident in the time leading up to a fire. Deliberate obstruction or damage to CCTV cameras may also be indicators of crime concealment. Consideration as to when and how this damage occurred must be given. It is not uncommon for poor maintenance of these systems to play a role in the difficulties obtaining this kind of evidence.
Interrogate security and fire alarm systems
The interrogation of security alarm systems can also prove critical in the investigation of deliberate acts. Alarm logs can provide access and egress information to either support or repute witness evidence. But they can also provide evidence as to an individual’s routine. For example, in one case, the alarm log showed consistent setting of the alarm on a nightly basis, despite the occupants being abroad, until the night of the fire.
Similarly, the deactivation or destruction of fire protection and suppression equipment such as fire suppression systems, sprinklers, and fire alarm systems may be indicators that support the intention of fire spread and crime concealment. Research into the service and maintenance of such systems must be undertaken to eliminate the possibility the deactivation or failure of such systems is not from lack of maintenance. The interrogation of the fire alarm panel will provide information with regard to any connected devices including those of sprinkler systems. This can give historical information regarding activations within the property, which may prove beneficial when considering if the fire is deliberate or through poor running of the site, in particular in commercial premises.
Care must be taken when interrogating the evidence obtained from fire and security alarm panels and CCTV hard drives as the evidence within these items can be rewritten or removed due to system activations or actions taken when trying to obtain this evidence. As such, it is recommended that a trained specialist be used for the gathering of this type of data.
Analyse utility and household items
Analysis of electricity, gas, or water meter readings may be beneficial when investigating arson-related insurance fraud in particular as they can assist in determining the occupancy of the property and confirm or refute witness evidence with regard to the circumstances of the incident. In the past, investigators have used pre-pay meter readings to demonstrate that a property alleged to be occupied had remained unoccupied for several months before the fire.
Analysis of dates on food items, newspapers, and post may also be beneficial in establishing the accuracy of an alleged timeline. The review of post and other documents within the scene may also provide indications of financial stress and a possible motive.
Combustion factors
Forensic analysis of the scene must be undertaken to determine the origin(s) of the fire and consider any materials involved including any possible ignition sources. A lack of ignition sources, improbable locations of a fire, and multiple seats of fire may be indicative of acts of arson. When considering lack of ignition sources and improbable locations, investigators must keep in mind the disturbance to a scene and whether any ignition sources may have been removed or displaced by others.
Areas of fire damage with no explainable ignition source or method of fire spread may be possible secondary seats of fire. The analysis of fire damage patterns will assist in determining if the damage observed is from fire spread or a separate seat of fire. In order to determine if a fire is multi-seated an investigator must consider each potential ‘seat’ of fire and explain why it has not occurred as a result of spread from one of the other seats. Investigators must bear in mind that aspects of building construction such as missing fire stopping and gaps created by service penetrations may contribute to spread of a fire outwith the area of origin.
The presence of ignitable liquids or incendiary devices and items piled up to assist the spread of fire can all be supportive indicators of arson. Where the presence of ignitable liquids is suspected, the material upon which the liquid is possibly present must be collected and packaged appropriately for testing. A control sample of the same material with no damage should also be collected. Samples could be sections of cushions, bedding, carpet, floorboard, clothing, and even soil samples. Appropriate packaging can be glass jars, clean metal tins, or more commonly, double bagging the item using nylon bags. A positive test result for ignitable liquids such as petrol, diesel, or kerosene would be required to confirm that an ignitable liquid has been used.
It is not uncommon in investigations for ignitable liquids to be present due to the use of generators or other diesel/petrol-operated appliances being located, used, or filled in and around the area of the fire scene. Care must be taken by the investigator to confirm that the presence of the ignitable liquid cannot be explained by any other possible cause.
Circumstance factors
Suspicious circumstances and witness behaviours can also raise red flags during a fire investigation. The forensic investigator may find that witnesses are unwilling or difficult to speak with, that their usual routines and activities changed in the lead up to the fire, or that they are overly interested in the investigation or any rectification works. Caution must be taken when considering the behaviours of witnesses as people’s responses to stressors and traumatic events such as fires can vary.
Additionally, with regard to insurance fraud, there may be indications that valuable items had been removed before the fire, possibly replaced with lesser value items and that fire-damaged remains do not match items claimed as lost in the fire. The forensic investigator may also discover that the fire was concentrated on financial documents or occurred during a renovation or property sale. All of these instances can point to potential arson.
A history of fires, multiple fires in the same geographical area, and the same person being present at multiple fire scenes may also be circumstantial indicators of arson.
Conclusion
A detailed and thorough analysis of the scene and all the evidence gathered is required to adequately consider and eliminate all possible natural or accidental fire causes, in order to determine that a fire has been deliberately committed. It is likely that a combination of the key indicators discussed above will be present for this determination to be made.
The strength and success of the determination will be dependent on a number of factors such as the initial control of the scene, the minimisation of disturbance to it, the forensic analysis of the scene, and the detailed and thorough gathering and recording of evidence. These actions, along with the prompt appointment of forensics, whether private or public sector will assist in maximising a successful investigation.
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Kiera Biggins is a Senior Investigator for Jensen Hughes.