List of terms, definitions and concepts

On this page, wherever possible, clear terms and their definitions are set out. These are shown in italics. In other cases, where attempting a fixed definition may not be straightforward or helpful at the present state of the art, the concepts are addressed more discursively.

Other relevant pages:

Paul Ekblom has endeavoured to maintain consistency and continuity with his own and others’ terms and definitions and avoid gaps and overlaps. However, due to ideas evolving over time, fresh inputs from other disciplines, and designing the terms for different purposes and aimed at different groups and professions, the definitions will continue to need some refinement. And the designer’s notion of ‘most advanced yet acceptable’ has sometimes required compromise over maximum clarity.

Crime and criminal events

Curiously, Crime Science has paid very little attention to defining the concept of crime, preferring instead to just get on with the job of reducing it. This is not particularly scientific! An attempt to remedy this follows.

Crime can be considered both as events and the acts that define them; and it can be viewed from a societal or cultural level. The cyber dimension of crime and security is still rapidly evolving. However, most of the concepts defined here are done so in a way that straddles cyber and material worlds. Exceptions that emerge will be incorporated into the definitions.

Criminal events

Crime at societal/ cultural level

  • Moral (e.g. guilt at not winning fair-and-square; shame at failing as role model)
  • Reputational (e.g. keep fans and commercial advertising opportunities by maintaining reputation of a fair player)
  • Institutional (e.g. civil or criminal bans on performance-enhancing drugs)
  • Security (e.g. testing for specific drugs and banning athletes showing positive)

Crime prevention

Crime prevention short definition

Crime prevention long version

The preventive actions should: comprise interventions intelligently-targeted on problems, contexts, causes, risk/protective factors or criminal goals; be appropriate for all stakeholders; be proportionate to problem and resources; be ethically acceptable; be limited in adverse effects; support multiple societal goals; where possible, be based on reliable and valid evidence and/or tested theoretical and practical principles; And be implemented and evaluated in such a way as to contribute to the knowledge pool of reliable evidence, tested theory and experience-honed practice.

Crime prevention definition-in-depth

Definition-in-depth means that the various elements of the above definitions must themselves be explained, in a suite which is consistent both internally, and with the various Crime Frameworks on this site. So, the technical ones first:

And now the normative requirements for preventive action:

Crime prevention supporting concepts


Situation, setting, environment, context

Situation and setting

In view of this, the distinction between setting and situation that Situational Action Theory (Wikström 2018; Bouhana 2019; Hardie 2020) makes is worth adopting, in modified form:

  • The setting is that part of the environment in which the criminal event occurs, or is close to in space and time, to which the individual is directly exposed, perceives and reacts. The setting can be material or informational, near or remote (as in crimes of telepresence) and any combination thereof.
  • The situation is that nexus in which the processes of precipitation, perception of action alternatives, the making of choices and initiation of a criminal act occurs, through interaction between the properties and dynamics of the setting, and the criminal propensity, resources, mental state and prior plans of the offender.

While situations are highly interactional in complex and subtle ways, settings are not entirely devoid of interaction. For example, the fact that an individual cannot perceive and respond to anything over that particular high wall says as much about them – their height, reliance on visible light, ways of perceiving things and optional possession of resources such as a periscope – as it does about the construction and material properties of the wall.


The term ‘environment’ is used in diverse ways (system theory, environmental criminology, CPTED, environmental or developmental psychology). It is challenging to construct a definition, that clearly distinguishes it from situations and settings, but here is a first attempt that owes most to system theory:

The environment of a given agent, object or system is anything during their existence with which they can exchange matter, energy and information, over greater or lesser spans of time and space.

Crime Science can probably safely ignore issues of special and general relativity, the expanding universe and quantum entanglement for now. Regarding environments, it should be noted, though, that:


Opportunity, affordance, opportunity structure


The ecological (as opposed to developmental/sociological) concept of opportunity can thus be defined as a joint property of agents, their resources and the setting in which: they are actually or potentially present or telepresent, whether through a chance encounter or as a result of deliberate search or act of creation; are able to perceive relevant information; and can act in furtherance of their goals.


Affordance comprises those action possibilities in the environment that are readily perceivable by an actor or agent.

The link from affordance to opportunity for committing crime or terrorism is taken further by Ekblom (2012d), Wortley (2012) and Bouhana (2019). And Situational Action Theory (Wikström 2018) refers to instances where those people who lack criminal propensity, simply fail to perceive the crime opportunity in a given situation, rather than being tempted but decide to resist. The link to the concept of offenders’ awareness space in Crime Pattern Theory (Brantingham et al. 2017) is also apparent – in familiarising themselves with various nodes and paths in their everyday routine environment (or during deliberate hostile reconnaissance) offenders can develop affordance of escape routes and ambush sites for example. The dynamics of opportunity seeking connects with the ecological concept of foraging as described in ‘optimal foraging theory’ approaches to criminal behaviour (Bernasco 2009).

Opportunity structure

Going beyond the here-and-now of individual opportunities, Clarke (1997) refers to opportunity structures, a term which lacked a clear definition (and see also a similar lack 20 years later in Freilich and Newman 2017). They could, though, be defined thus:

Opportunity structures are regularities in how society is construed, which repeatedly bring together the conditions for individual opportunities at particular places and times.

Again, note that these conditions include both environmental circumstances and offender resources for exploiting them, in interaction. The situational concept is of course distinct from the sociological use of opportunity structure e.g. by Cloward and Ohlin (1960) who cover legitimate vs. illegitimate developmental or career opportunities open to individuals growing up in different contexts.

The niche covers what career slot an offender can pursue or construct, with what resources they have in their repertoire/possession, in an environment with what opportunity structure.

Attack surface

The attack surface comprises the sum of all possible security risk exposures of some system.


Several aspects of the term ‘problem’ deserve clarification.

Defining ‘problem’

The term ‘problem’ in crime reduction terms could therefore be redefined at two levels as follows:

A crime problem is a particular manifestation of crime, e.g. a recurring set of similar criminal events, often but not always centred on a location, product, system, service or procedure, or a set of similar such instances. The problem to be solved is one of how to intervene to reduce that crime problem to acceptable levels, whilst also satisficing the wider set of goals of all legitimate stakeholders.

Reframing problems
Problems, opportunities and risks

Crime reduction and control

Crime reduction

Crime reduction is a broader and simpler concept than prevention, sometimes favoured in the UK. It has much in common with security. Although its originators never gave it a clear definition it is worth attempting this:

Crime reduction is any intervention made before, during or after criminal events to reduce their frequency or harm.

Crime control

Crime control is essentially crime reduction with performance targets. Total elimination of crime is impossible on both resource and effectiveness grounds (not to mention libertarian considerations – see Sutton et al. (2008) on Singaporean crime prevention). Crime control can have two meanings:

The ‘everyday’ meaning and aim of crime control is holding the frequency of criminal events, or their harm, below a tolerable level.

The ‘exceptional’ aim of crime control is halting rapid and disruptive growth in frequency or harm.

Major disruptions such as the Covid-19 pandemic put civil society under strain whilst simultaneously overloading the police and security services. The existence of fair and effective criminal, civil and procedural justice arguably makes a huge contribution to keeping these problems at bay; and avoiding events that jeopardise such justice (as with the police killing of George Floyd in Minnesota) is an important aspect of preventive policy and practice, as well as being a moral imperative.

Sometimes it’s necessary to think beyond everyday crime prevention and security. What might be called the ‘apocalyptic’ aim of crime control is the maintenance of civil society.

The maintenance of civil society embraces the control of a range of progressively more devastating systemic problems: corruption, particularly in the enforcement and judicial system; feuding and conflict and other forms of extreme and persistent disorder; the collapse of faith in the state as provider of fair and satisfying justice, and its substitution by vigilantism, violent self-defence, and even quasi-government by paramilitaries.

Community safety, community and partnership

Community safety tends towards a holistic view of crime problems, and of solutions. Paradoxically, this requires an even greater clarity and rigour, to understand what exactly the interventions are aiming to achieve and by what causal mechanisms they will do so. Without this, practical interventions often degenerate into well-meant but superficial and ineffectual efforts with drifting objectives.

Community safety: short version

Community safety is an aspect of the individual and collective quality of life, in which people enjoy freedom from, and/or reassurance about, a range of real and perceived crime risks; can cope with harmful consequences of crime, if necessary with help; have confidence that the police and other agencies will provide a responsive, fair and effective service delivering justice and broader remedies; trust and moral order is upheld; and conflicts are resolved. Meeting these conditions enables people to pursue the necessities of life; receive adequate services; exercise skills; experience well-being; engage in community life; and create wealth in the widest sense.

Community safety: long version

Community safety is an aspect of the quality of life, a state of existence in which people, individually, collectively and in organisations, and in public and private space, enjoy the following crime-related conditions:

  • Freedom from and/or reassurance about a range of real and perceived risks centring on crime, antisocial behaviour, disorder and drug dealing and abuse – including freedom from fear of crime.
  • Ability to cope with the harmful consequences of those incidents they nevertheless experience, at reasonable cost (e.g. without curtailment of going out).
  • Help to cope if unable to do so alone, whether informally from the community, or more formally by, say, victim support or insurance.
  • Confidence that the police, Criminal Justice System and other agencies will, if needed, provide a responsive, fair and effective service that delivers justice and broader remedies to the problems and conflicts they experience or risks they perceive.
  • Trust – within and across cultural boundaries – in neighbours, colleagues and passers-by, to support them both morally and materially in terms of sympathy; existence of collectively-upheld moral order, social control and support; and trust in police and other enforcement-empowered services, to behave fairly and decently towards those that they must confront.
  • Avoidance and resolution of civil conflicts with the potential to turn criminal.

When all these conditions are sufficiently met, they enable individuals, families and, communities to enjoy these wider benefits:

  • Pursuing the necessities of cultural, social and economic life
  • Receiving adequate services
  • Exercising skills
  • Experiencing well-being
  • Engaging in community life
  • Creating wealth in the widest sense
  • Particularly where social cohesion and collective efficacy and an obligation to reciprocate develop, the above conditions contribute to the community’s own capacity to address crime and disorder in collaboration with official institutions without making informal social control oppressive, invasive or exclusionary, or taking the law into their own hands; and to the development of sustainable communities.


It’s particularly important to address the concept and institution of community, a term used with some abandon within the crime prevention field (community policing, community safety, community crime prevention, even punishment in the community) and beyond. To act and to document effectively, those engaged in community safety must be able to navigate this particular semantic sea (see also Jamieson 2008). Wiles and Pease (2000) also warn against the ‘fluffy’ connotation of ‘community’ which may privilege ‘social’ or offender-oriented action over other kinds. But the wide range of meanings of the term ‘community’ itself is challenging. Proposed here is a minimalist definition, supplemented by the elaboration of a set of alternative aspects of community. Those who use the term should declare which aspect/s they are addressing.

Communities comprise sets of people with a common interest or sense of identity and usually some means of communication, collaboration and exchange. They can cover particular geographical territories (such as neighbourhoods), or spatially diffuse groupings (such as ethnic minority groupings). They can exist at different scales, from families to societies, and may be nested or cross-linked.

  • A community itself (or its physical components like high streets or community centres) can be a collective target of crime in receipt of crime prevention/security initiatives.
  • A community can be a source of crime meriting preventive action – simply by being composed of many criminally predisposed members, or by the emergent contribution of a criminal subculture. The crime can afflict members of the same community, other neighbourhoods or (for example) the town centre.
  • A community can be a setting where crime preventive interventions are planned and implemented, with a key ingredient being the participation and ownership on the part of community members and organisations in identifying problems, and planning and implementing solutions.
  • Community safety can exploit specific community crime prevention mechanisms, including informal social control or support processes, in the intervention itself. It can also tackle the social conditions and influences which act at a community level to generate crime (or radicalisation – cf. Bouhana’s 2019 ‘moral ecology’ concept). Offenders, victims and other crime preventers may be linked by pre-existing civil community relationships (such as pupil-teacher, landlord-tenant, employer-employee, neighbours – see Crime Role Grid) which may be the source of conflict and/or offer the prospect of resolving it. Interventions may enhance the general capacity of a community to protect or control by developing social structures such as residents’ associations, and/or by improving trust and social cohesion among members. Interventions may also empower through provision of specific resources, such as property marking tool-libraries or transport for young people to legitimate entertainment facilities.


Partnership is an institutional arrangement that shades into a philosophy. It is a way of enhancing performance in the delivery of a common goal, by the taking of joint responsibility and the pooling of resources by different agents, whether these are public or private, collective or individual. The added value from such a collaborative approach usually stems from an enhanced ability to tackle problems whose solutions span the division of labour, and/or centre on a particular locality. The agents in partnership may bring with them conflicting or competing interests, and different perspectives, ideologies and cultures – so in democratic and legally-regulated contexts they seek to act together without loss of their separate professional identities, without unacceptable or illegal blurring of powers and interests, and without loss of accountability.

Partnership definition-in-depth

It’s helpful to expand the definition of partnership to include the various subsidiary terms, otherwise considerable ambiguity would remain embedded in the concept.

  • Partners may include such agents as institutions, communities and/or individuals. Professional expertise is usually involved but often in conjunction with lay individuals or organisations. The distinctive contribution of the last two rests on intimate local knowledge, influential relationships and grassroots legitimacy; and on simply supplying wide territorial coverage (local people and institutions are in the right place for much of the right time). Co-operation between agents with diverse identities and natures is taken here as a defining feature of partnership relations. These relations will inevitably involve conflicting, or at least competing, main goals and mandates; and perhaps also differing ideologies, cultures and perspectives. Some tension must therefore be overcome before a worthwhile partnership relation begins.
  • To counter this tension partnership usually involves some kind of institutional agreement between the partners – whether informal or formal, and even contractual or legal. Legal formalities involve the local or national state. They may be required by wider governmental law or practice. However, depending on context, they may not always be necessary from a practical view: it is usually in the interests of the partners to honour the agreement without any external pressure. In some countries partnerships are not legal entities, but some legal provisions apply to their activities, e.g. professional secrecy regarding sensitive personal information, although these provisions are ‘loosened’ a little compared with the general rules.
  • Typical partner agents (in a range of horizontal and vertical relationships) include: State and municipalities (central/local). Public sector/ NGO and citizen organisations (state power/ citizens) – but citizens are rarely involved as individuals, usually as members of organisations such as residents’ associations. Law enforcement, social welfare, employment, health, education, culture and town planning. Authorities and private economy (state power/ markets) – mostly with umbrella organisations representing particular industries such as insurance, or trade/ labour/ employers’ unions; but sometimes with local groups such as retailers in a particular shopping centre, or even individual companies. In many countries, links with the last, including sponsorship, are not permitted. Communities are as defined in the above section.
  • The partnership goal in question may be an ultimate one (usually crime prevention, or perhaps tackling the consequences of crime for quality of social and economic life); an intermediate objective on the direct route to that goal (e.g. strategically identifying a specific crime problem to tackle, or delivering a service which will reduce the risk of crime); or a supporting task (e.g. removing some constraining influence such as excessively rigid fire regulations which inhibit security measures in buildings).
  • Responsibilities for crime in the sense used here are, of course, those for preventing it or for dealing with its consequences. The responsibilities are usually formally acknowledged. They may derive from statute or custom; negotiated; or self-imposed, stemming from altruism or mutual self-interest. Responsibility has three aspects for which the partnership may be held to account – achievement of the goalnon-interference with other goals (such as privacy or wealth creation); and handling failure or disaster. Responsibility for these risks, too, is shared by partnerships. In this there is usually a degree of solidarity and mutual support among partners.
  • Resources are what are used to achieve a goal. They comprise inputs such as basic funds and personnel time, and raw materials such as information on crime; and capacity to transform inputs into outputs to achieve the desired goals. Capacity in turn comprises assets such as legal powers and wider moral legitimacy; organisational structures and processes including trust within and between partner organisations; physical equipmentICT systems; and knowledge.
  • Pooling of resources may be done for several reasons which are quantitative (e.g. strength in numbers, economy of scale), qualitative (e.g. complementary knowledge and skills) or both. Pooling may serve to enhance performance in pursuit of the partnership’s goal, and legitimacy or acceptability of that performance to society as a whole. In this last respect, the symbolic involvement of a particular institution or individuals may be more important than the material resources they can bring. This is especially the case where, for example, a partner has moved from being an inadvertent ‘crime promoter’ (through its everyday activity in, say, producing goods vulnerable to criminal damage) to a ‘crime preventer’ (to continue the example, where it now designs goods that are damage resistant).
  • Pooling may be done in diverse ways, described here for convenience as polar opposites: short- or long-termstrategic or tacticalshallow (e.g. systematic cross-referral of cases between otherwise independent agencies) or deep (e.g. joint strategy, or joint organisation); covering a single goal or a broad set of related goalsinternal (e.g. between the departments of a local authority) or external (e.g. between the local authority and the police); horizontal (e.g. all agents within a locality) or vertical (e.g. between national and local government).

Related concepts to partnership include:

  • Co-ordination – this differs from partnership in that there is mutual agreement and a temporary uniting of interests without formal adoption and pursuit of a common goal between the collaborators, and no consequent pooling of resources.
  • Networks – these comprise open-ended structures of informal contacts in which mainly sporadic exchange of information, resources or advice is achieved.

Besides the immediately practical, goal-directed aspects focused on here, partnership can also be viewed as a philosophy of governance – a collective state of mind which contributes to a climate of support. Of course, philosophy without the practicality can lead to pseudo-partnerships – where one agency holds all the power beneath a show of mutuality – and fashion. Lip-service to partnership ideals can lead to collapse when tough commitments and decisions have to be made, and partners find they have to go in different directions; or when proceeding along the same path, encounter diverse constraints.

Partnership definition – background

The paper first develops the meaning of the term ‘partnership’, by focusing in progressive detail on the key concepts on which the term is built. It then focuses in a similar way on crime prevention and related concepts such as crime reduction and community safety. This is followed by a discussion of why crime prevention in particular needs a partnership approach; an analysis of responsibility for delivering crime prevention; and a further exploration of some central dimensions of prevention, relating in particular to the concept of community. Then, in a change of direction, the paper considers problems and costs of partnership, and a design-based approach to overcoming or controlling these costs whilst securing the benefits. This includes a discussion of evaluation.

Security and risk management, hazards and threats


Note: there’s no direct connection of the above with ‘primary, secondary and tertiary prevention’ (Brantingham and Faust 1976). These are risk-based targeting strategies and more meaningfully named ‘universal, selective and indicated’ (Mrazek and Haggerty 1994; Wilson and Lipsey 2007). They are typically applied to offender-oriented interventions (e.g. all young people; those judged at particular risk of offending; those who have offended) but van Dijk and de Waard 1991 have also applied the original ‘primary, secondary, tertiary prevention categories to situational, offender-oriented and community-based prevention to derive a six-fold classification.

A notable mixed example is the ‘once bitten’ strategy (Farrell and Pease 1993) against burglary which targets all households for primary/universal prevention; those with elevated risk through repeat victimisation for tertiary/indicated prevention; and if that fails, attempting to target offenders with a range of secondary/tertiary strategies.

  • Prevent – offender- or community-oriented intervention to prevent radicalisation
  • Protect – defence of targets and places against attack
  • Prepare – making buildings, emergency teams etc ready to mitigate the impact of a terrorist attack e.g. by first response and also improving resilience
  • Pursue – undertaking law enforcement against offenders during planning or after the event.

Risk and risk management, hazard, harm, threat


Risk can be used as a strategy for targeting security and crime prevention. It also features in Situational Crime Prevention (SCP) as something the offender wants to reduce, i.e. implicitly the risk of arrest or other adverse consequences. There has however been little attention to teasing out the wider concept of risk. Since SCP was founded, the concepts of risk in general and in security in particular have moved on and it’s important to keep up, otherwise SCP practitioners (and researchers) will find it increasingly difficult to communicate, share knowledge and collaborate with those working within mainstream security, and in wider risk-related fields.

The risk management process
  • Avoiding the risk by deciding not to start or continue with the activity that gives rise to the risk
  • Accepting or increasing the risk in order to pursue an opportunity
  • Sharing the risk with another party or parties (including contracts and risk financing)
  • Retaining the risk by informed decision
  • Removing the risk source
  • Changing the likelihood
  • Changing the consequences

The last three, risk treatment interventions, are of course what crime prevention is about.

From a strategic perspective, security involves systematically:


What are hazards and threats and how do these relate to risk?

There is a need to distinguish between risk, hazard and threat, although these are commonly used loosely.

A hazard is a source with causal potential to do harm, whether on its own or in conjunction with other contextual factors. That potential amounts to the risk associated with/given the presence of the source and its context.

  • Sources (e.g. moving machinery, radiation or energy sources)
  • Situations (e.g. working in confined spaces, working at height)
  • Acts (e.g. manual handling, wearing PPE)

Crime-related equivalent examples can be readily envisaged. Offenders may constitute a source (e.g. of violence) and may exploit other hazards, either bringing weapons with them or using those that are available in situ. For example, they could detonate an on-site fuel tank to destroy a major station.


Sparrow (2016) discusses police work in terms of its wider governance context, referring to ‘risk-based regulatory practice’. But he goes further to distinguish the unique aspect of policing and crime prevention, as having to deal with opponents who deliberately seek to evade detection and adapt strategies to circumvent control initiatives. We can go with this distinction and define thus:

A threat, in the security sense (as opposed to an offender making threats), is a hazard created, activated or directed through adaptive human malintent.

All hazards approach

Resilience – beyond prevention and preparedness

Relying solely on prevention and preparedness to mitigate risks, assumes that we are able to anticipate the kinds of adverse events that we wish to avoid; or, if necessary, to adequately respond to them. This assumption may be false. Our predictions can be wrong for several reasons:

For these reasons, to handle the ‘unknown unknowns’, risk-specific prevention and preparedness must be complemented by something more generic – resilience.


Connecting with the above discussion of security, resilience combines the capacity to deliver secondary and tertiary security, and mitigation. More strategically thinking, Edwards (2009) defines resilience as the capacity of an individual, community or system to adapt in order to sustain an acceptable level of function, structure, and identity.

Definitions are diverse, reflecting a wide range of practical and theoretical approaches and disciplines, but these are the recurrent elements:

Resilience is the capacity of some individual, group, community, system or item of technology to avoid, resist or absorb harmful events (e.g. crimes, civil emergencies), either whilst continuing to function or with the ability to be restored to function; and then to reorganise and adapt to changes. The harms encountered may or may not have been anticipated, hence advance preparations to instil resilience must always include those that are generalised in nature, such as redundancy and flexibility.