The psychology of an arsonist

15 December 2025

When the trade press reports a serious commercial fire in the UK, one of the first questions in the subsequent investigation is almost always whether the fire was deliberate. Often it was. Deliberate fires account for a substantial share of fires attended by UK fire and rescue services each year, and when the figures are broken down to non-dwelling buildings, including commercial, industrial and public premises, the picture is that tens of thousands of deliberate fires happen annually. A meaningful proportion of warehouse fires, school fires, derelict building fires and multi-tenanted commercial fires are set on purpose, by someone who had a reason, even if that reason would strike most people as thin, and who chose the building in question because it offered them something the next building along did not.

For responsible persons, managing agents and owners, understanding something about the psychology and patterns of deliberate fire setting is useful in the way that understanding the basic mechanics of burglary is useful, which is to say that it shifts the conversation from "why would anyone do this to us" to "what is it about our building that makes it the easier choice". The second conversation is the one that produces action, and it is the one this article is about. None of the material below is profiling guidance, and none of it is designed to help anyone spot an arsonist in a crowd. It is about how buildings become targets, and what a competent approach to arson risk looks like inside a modern fire risk assessment.

Arson as a foreseeable fire safety risk

Deliberate ignition is a fire hazard in the ordinary meaning of the phrase, and the Regulatory Reform (Fire Safety) Order 2005 does not distinguish between fires that start by accident and fires that start on purpose. The responsible person's duty under Article 9 is to carry out a suitable and sufficient fire risk assessment that identifies hazards and evaluates the risks they present, and where arson is a foreseeable risk for the premises, it belongs in the assessment alongside cooking, electrical fault, smoking and everything else. For warehouses, schools, places of worship, heritage premises, buildings with external combustible storage, buildings in locations with a history of deliberate fires, and anywhere the pattern of the building's use lends itself to unobserved external access, foreseeability is usually easily established, and the assessment should address it.

Enforcing authorities who examine a building after a deliberate fire will look at the fire risk assessment and ask whether the arson risk was addressed, and whether the controls the assessment recommended were in place and working. The answer matters to the enforcement position, and it matters to insurers, most of whom include specific policy conditions around housekeeping, external storage and out-of-hours security precisely because they know what the statistics say about deliberate fires and the buildings that attract them.

What the research tells us about motive

The most durable framework in this area remains the motive typology developed by the FBI's Behavioral Science Unit in the late twentieth century and refined in the research literature since, which groups deliberate fire setters by the reason they offer or appear to have had for acting. The categories are imperfect, individuals often fit more than one, and the framework is not intended to diagnose anyone, but it is a usable shorthand for the patterns property professionals actually encounter.

Revenge

Revenge is the most commonly identified single motive across several UK and international studies of convicted arsonists, and it covers fires set against a person, an organisation or an institution in response to a perceived grievance. Former partners, former employees, disgruntled tenants, evicted occupants and customers with a complaint against a business are all well-represented in the case literature. Revenge fires tend to be directed at specific premises the offender has a connection to, they tend to be set at entry points, service areas or places the offender knows are vulnerable, and they often show evidence of forethought without necessarily showing evidence of sophistication.

Vandalism

Vandalism fires are set for the sake of damage itself, frequently by young offenders, frequently in groups, and frequently as part of a wider pattern of antisocial behaviour in an area. Wheelie bins, bin stores, abandoned furniture, skips, derelict buildings, outbuildings, and the unloved corners of otherwise well-kept premises are disproportionately represented among vandalism targets. Schools, particularly out of hours and during school holidays, feature heavily in the UK statistics for this category, which is one reason why school arson receives specific policy attention from fire and rescue services.

Excitement

Excitement-motivated fire setting is the category most people picture when they hear the word arsonist, even though it is a relatively small share of the total. Fires are set for the sensation, the attention or the drama, sometimes by offenders who stay to watch or who return to the scene, and sometimes by offenders who make anonymous calls reporting the fires they have set. Serial offenders with this motive pattern exist and are the subject of a considerable body of research in forensic psychology, but the more common version is the one-off offender acting out in a moment of emotional arousal.

Profit

Profit-motivated arson covers insurance fraud, destruction of stock or records, disposal of unwanted buildings, intimidation of commercial rivals and the related family of offences in which fire is a tool to a commercial or financial end. Profit fires are typically set in premises the offender owns, controls or has legitimate access to, which is why they so often present investigators with evidence of an inside job, including unexplained absence of stock, disabled alarms and removed sentimental items before the fire. The category is significant to insurers and accounts for a disproportionate share of the financial loss associated with deliberate fires.

Crime concealment

Fires set to destroy evidence of another crime appear across the spectrum, from burglaries where the offender sets the premises on fire on their way out to much more serious offences where fire is used to destroy a body or forensic evidence. From a building-risk perspective the pattern matters because crime-concealment fires are overlaid on another offence that has already breached the building's security, which tends to mean the premises that are vulnerable to burglary are also vulnerable to this category of arson.

Extremism and protest

Fire is used as a tool of intimidation, protest and terror by a variety of actors, historically and currently, and the premises most likely to be affected are those with a political, religious or symbolic profile, including places of worship, political offices, animal research facilities and premises associated with controversial industries. This category is numerically small but disproportionately consequential, and for premises with a recognisable profile it is a risk that belongs on the assessment even when the probability in any given year is low.

Other and complex cases

A small minority of deliberate fires are set by individuals whose behaviour is linked to serious mental illness, neurodevelopmental conditions or long-running patterns of harmful behaviour. Only qualified clinicians can assess such cases, and nothing in fire risk assessment practice depends on doing so. The property angle is the same regardless of the underlying psychology, which is that the building offered an opportunity and the individual took it.

Opportunity, target selection and the building's role

Across all the motive categories above, one finding recurs often enough to be treated as a working assumption: deliberate fires are overwhelmingly set in premises the offender has chosen, and the choice is driven heavily by opportunity. Premises that offer concealment, easy access to combustibles, easy approach and departure routes, and low probability of interruption are chosen more frequently than premises that do not. Research on convicted arsonists indicates that planning is present in many cases even where the offender was under the influence or emotionally disturbed, and the planning that does take place is often about location rather than method, with the offender settling on a target they have observed or known about rather than improvising on a building they happen to pass.

This is the finding that makes arson tractable from a fire risk assessment perspective. Motive is not something the responsible person can manage, but opportunity is, and the building features that attract deliberate fire setters are, in most cases, the same features that good housekeeping and sensible premises management would address anyway.

The building features that attract deliberate fire

The framework that crime prevention specialists use for thinking about the built environment is Crime Prevention Through Environmental Design, usually abbreviated to CPTED, which organises mitigation around natural surveillance, access control, territorial reinforcement and maintenance. Applied to arson, the features that make a premises easier to target are the ones that undermine one or more of these principles. The common patterns are recognisable from the statistics and from any walk-around of a poorly-kept commercial site.

• External combustibles in approachable locations, including wheelie bins and bin stores adjacent to the building envelope, accumulated cardboard and packaging at loading bays, stored pallets and abandoned furniture, and overgrown vegetation against walls and fences.
• Concealed approach and departure routes, including unlit service yards, alleys behind retail and industrial units, hidden smoking areas, external stairwells out of sight of the main elevations, and routes into the site that do not pass any natural surveillance.
• Easy access points, including unlocked plant rooms and service cupboards, propped-open fire doors, accessible flat roofs and rooflight arrays, forcible entry points that have not been repaired after previous incidents, and service corridors or basements shared between tenants where control of access is weak.
• Signs of neglect, including broken windows left unrepaired, graffiti that has been allowed to remain, accumulated litter, vacant parts of the building with no obvious activity, and lighting that is failed, dim or missing.
• Shared or concealed voids, including roof spaces between units in mixed-use buildings, interconnected ductwork or services, and voids in heritage premises where hidden ignition can develop before it is noticed.

None of these features causes arson, and plenty of well-run premises have one or two of them without consequence. What they do is shift the odds. A motivated offender surveying two similar premises will routinely choose the one that offers the better opportunity, and a responsible person who treats the list above as a working inspection brief during premises walk-arounds will, over time, visibly reduce the attractiveness of their site.

The working inspection question is not whether your premises could be targeted in principle, which any premises could, but whether the external and out-of-hours condition of the building silently invites a passing offender to consider it. Ten minutes with a clipboard, walking the perimeter at dusk, is one of the more useful things a responsible person can do, and it tends to identify the same handful of issues every time: combustibles too close to the building, light levels that are lower than they used to be, and doors or hatches that are quietly unlocked.

What a competent arson mitigation approach looks like

The controls that reduce arson risk are, with a handful of exceptions, measures any competent premises management should be running anyway. The fire risk assessment is the document that ties them to the specific building and to the specific threat, and a good assessment addresses arson in terms the responsible person can act on.

On the physical side, this means securing external areas at the close of business, locking bin stores and moving wheelie bins clear of the building envelope, maintaining external lighting, keeping the site free of accumulated combustibles, controlling access to plant rooms, service risers and roof spaces, and repairing visible damage and signs of neglect rather than living with them. On the management side, it means supervising external works and deliveries so that combustibles do not accumulate unnoticed, reviewing CCTV and access arrangements periodically against who is actually using the building, taking patterns of small fires or suspicious activity seriously rather than dismissing them as unrelated nuisances, and working with local fire and rescue service community safety teams, many of whom run specific deliberate fire reduction programmes aimed at commercial premises.

Out-of-hours is where most deliberate fires are set, and the out-of-hours condition of the building is the one most easily overlooked because nobody sees it. A site walk at the end of the working day, carried out by someone whose job it is to leave the premises in a defensible state for the night, is worth more than several pages of policy. So is a clear arrangement with tenants, contractors and cleaners about who is responsible for what, because arson risk often accumulates in the gaps between responsibilities rather than within any one person's remit.

Insurance, claims and the arson clause

Commercial fire insurance policies almost always include specific conditions relating to arson risk, and failure to meet them is one of the common reasons claims are delayed, reduced or repudiated after a deliberate fire. Typical conditions include housekeeping requirements limiting the accumulation of combustible waste, external storage requirements keeping combustibles a defined distance from the building, out-of-hours security provisions, restrictions on hot works and temporary trades on site, and requirements to report increases in risk, such as vacant units or changes of use, before they materialise. None of these is unusual and none is unreasonable, but they are easily forgotten and they typically apply at the moment of a claim, not at the moment of the underwriting.

The fire risk assessment is a useful document in this context because it sits alongside the insurance schedule and describes the actual state of the premises, and a claim handler examining a post-fire file will often look at the assessment and the insurance conditions side by side. Inconsistencies between what the insurance assumes about the building and what the assessment finds about it are uncomfortable territory for the insured, and worth reconciling in advance of any incident.

Reporting concerns without overstepping

Occasionally staff, tenants or residents raise concerns about someone's behaviour around fire, either specific behaviour at the premises or worrying conduct reported from elsewhere. The right response is to take the report seriously as information, record it through the normal risk management process, and, where concerns suggest a safeguarding or criminal justice issue, involve the appropriate services, which may include the local fire and rescue service community safety team, the police, adult or children's social care, or relevant health services depending on the circumstances. Diagnosis is not the responsible person's role, and neither is investigation. What the responsible person can do is make sure that information of this kind is captured, considered in the risk picture for the premises, and passed to the people whose job it is to act on it.

A practical starting point

If arson has not been considered in the current fire risk assessment for the premises, or if it has been mentioned only in general terms without reference to the specific features of the building, updating the assessment is the starting point. A competent assessor will look at the site with the arson question in mind, consider it alongside the other hazards, and recommend a proportionate set of controls. The controls themselves are usually inexpensive, often just the sensible version of things that are already in place, and the cumulative effect of addressing them is a building that a motivated offender is more likely to walk past than to walk into.

Arson Risk and Fire Risk Assessments in Chester, the North West and North Wales

Fletcher Risk carries out fire risk assessments that consider arson risk alongside the other hazards for premises across Chester, Cheshire, the Wirral, the North West and North Wales. We look at the site, the building, the management arrangements and the out-of-hours picture, and we set out a proportionate set of controls that can be maintained as part of normal premises management. If you would like to discuss the arson risk picture for your building, or arrange a full fire risk assessment, please get in touch.

Book a Fire Risk Assessment Get in Touch

This article is provided for general information only and does not constitute legal, clinical or professional advice. It does not describe how to identify individuals at risk of setting fires and should not be used for that purpose. Arson risk and appropriate controls depend on the specific premises, location, use and management arrangements, and should be considered within a suitable and sufficient fire risk assessment carried out by a competent person. References to legislation, research and industry practice reflect general understanding at the time of publication and should be verified against current sources before being acted upon.