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Crime prevention features

Understanding the Dimensions of Crime Prevention Interventions

Crime prevention interventions can be characterised in many different ways. The College of Policing’s Crime Reduction Toolkit and its underpinning EMMIE framework provide a robust approach for assessing what works to reduce crime. But applying that knowledge in practice requires us to think carefully about how specific interventions will interact with the spatial and temporal characteristics of the problems they are intended to address. Understanding not just whether something works, but where, when, and under what conditions, is crucial for matching interventions to the dynamics of crime on the ground.

To illustrate this, consider two contrasting approaches: foot patrol and hotspot problem-solving.

Foot patrol can be deployed quickly in small, targeted areas. It tends to have immediate but short-lived effects, and its impact is usually limited to specific offence types in the area directly patrolled. This can make it a good fit for transient hotspots - places where crime temporarily flares up and needs rapid, visible deterrence.

Patrol exemplifies interventions that are quick to start but quick to fade, suited to problems that move or evolve rapidly.

By contrast, hotspot problem-solving - a form of Problem-Oriented Policing (POP) often delivered through tailored situational crime prevention measures - is designed for persistent, stable hotspots. This approach focuses on diagnosing the underlying causes of recurring problems and implementing changes to the environment, management practices, or local routines. Examples include improved lighting, access control, street layout changes, or co-ordinated multi-agency activity.

Such approaches require time: time to analyse patterns of harm, time to co-design a response with partners, and time for the intervention to take effect. But once implemented, their impact can be durable, altering the conditions that allow the problem to persist. As such, POP is better suited to relatively stable hotspots where problems persist long enough to allow for effective diagnosis and implementation. In more dynamic environments, where problems shift rapidly in space or time, the delay inherent in this approach can make it harder to intervene before the issue has moved elsewhere.

Hotspot problem-solving therefore contrasts with patrol as an intervention that is slow to start but long to last.

Both strategies can be effective - but only when matched to the right context. To make informed decisions then, we need to understand the different dimensions that shape how, where, and why an intervention might work.

That’s why, when designing or assessing crime prevention interventions and how they may or may not match up with the crime problems we seek to adress, we probably need to ask a series of guiding questions to understand their underlying dimensions. These include practical constraints (such as cost and scalability), theoretical fit (the nature of the problem being targeted), and delivery characteristics (such as how quickly the intervention takes effect and how long evidence suggests its impact will last). Crucially, we need to consider how an intervention is likley to align with the spatial and temporal patterns of the problem in question: whether the issue is concentrated in a few persistent hotspots or is more dispersed and short-lived. Matching the scale and timing of an intervention to the observed distribution and dynamics of harm is essential for ensuring that resources are deployed effectively and sustainably.

Below is the (non-exhaustive) set of guiding questions we envisage being useful when reviewing interventions:

  • What is the intervention?

  • What type of offence is it targeting?
    The specific crime or harm the intervention is designed to address (e.g. ASB, knife crime, VAWG).

  • At what level or unit is it delivered?
    The spatial or institutional scale of implementation (e.g. street, school, neighbourhood).

  • How strong is the evidence that it works?
    What is the quality and consistency of the evidence supporting its effectiveness (e.g. RCTs, evaluations, expert consensus)?

  • How long do the effects last?
    After the intervention ends, for how long do its effects persist?

  • How quickly does it start working?
    What is the typical time lag between implementation and observable impact?

  • Roughly how much reduction in harm or crime might we expect?
    Based on available evaluations, what is the typical scale of change achieved (e.g. 10–20% reduction)?

  • Do the benefits spill over into nearby areas?
    Does the intervention show signs of producing positive effects beyond the targeted unit (i.e. diffusion of benefit)?

  • How much does it cost to deliver per unit?
    The estimated financial cost to implement one instance of the intervention, including staff time, materials, and overheads.

  • What might be potnetial unintended consequences? Some interventions have either been shown to generate uninentended consequences - or those consequences can be somewhat anticipated.

  • How many units could we treat?
    Given a typical funding/resource envelope, how many units (e.g. schools, streets, hotspots) could be feasibly covered?

We also know that the quality of evidence available to answer some of these questions can vary significantly across different interventions. That’s where a framework like EMMIE can help, by encouraging a structured assessment not just intervention effectiveness. Ultimately, understanding these dimensions helps decision-makers move beyond simply asking “does it work?” to asking “what works, for whom, in what contexts, and at what cost?” Only by engaging with these trade-offs can we design more effective, targeted, and scalable responses to crime.