Assessment – a problem-solving approach to homicide

Assessing the impact of your homicide prevention activity

First published

19 October 2022

Homicide problem-solving guide

5 mins read

Assessment forms part of the SARA model and can be used as part of a problem-solving approach to homicide.

Assessment forms the final stage of the SARA problem-solving process. It's the evaluation to determine whether the response has worked out as intended and whether the problem has been removed, reduced or unintentionally aggravated.

There are two main purposes of assessment in problem solving.

The first purpose deals with the here and now. It helps you determine whether a crime problem is persisting following the implementation of responses. Knowing this can help you decide whether further problem-solving efforts to address the problem are needed.
The second purpose is to learn lessons for the future – to understand how your efforts to reduce crime might inform your work going forward and to contribute to the wider evidence base about what is, and what is not, effective in tackling crime.

For the first purpose of assessment, it may be enough to know whether your local crime problem is persisting, regardless of whether your problem-solving work was responsible for any observed reductions.

For the second purpose of assessment, we need to know much more, including whether it was what you did that led to a decrease in crime and whether there were any side effects because of your activities.

This approach will help you and others know whether your responses are worth trying when tackling new crime problems.

Meeting the second purpose of assessment is challenging and will vary in its level of complexity depending on the:

scale of your local crime problem
nature of the responses implemented
skills and resources available

It is important to decide early in the problem-solving process what the purpose of the assessment is.

Deciding this has implications for what you do in other parts of the SARA process.

For example, if you are aiming to learn lessons for the future, you will need to start planning your measurements before any responses are put in place.

If you find that numbers of knife-enabled robberies have declined and then look for the evidence that what you did was responsible for those falls, it risks producing biased findings.

The primary aims of assessment are to:

determine whether the response has had a causal impact on the selected problem. For example, whether the outcome has been affected in the way you anticipated
document your learning to inform the continued delivery or adaptation of the response
inform future problem-solving activity in a new context and share with the wider homicide prevention community

Understanding the impact of a homicide intervention

There are things that an individual officer, analyst or force can do to better understand whether a homicide intervention is moving in the right direction. These involve measuring a combination of process, outputs and outcomes.

Wherever possible, these changes should be compared to a similar period of time to see whether there have been changes beyond what you would expect if the intervention was ineffective. For example, comparing violence in August to violence in September will almost always show a reduction because of changes in the weather and people’s activities. Calendar months can also have four or five weekends, which can invalidate comparisons for a night-time economy intervention.

If possible, you should also include a comparison area or group of individuals who have not been targeted. This helps to add another dimension to your assessment.

Record your activity

Firstly, in line with the theory of change you’ve developed, carefully record what activity was done.

Assess whether the actual activity matched the planned activity.

Assess to what extent and for how long the activity was implemented.
If there were deviations (and there almost always are), assess what impact these might have had on the target of the intervention.

Assess the intermediate outcomes

Secondly, if changes in homicide and near-miss homicide are too rare to identify over the short term, assess what intermediate outcomes can you use. These might include the precursors of homicide, such as strangulation in domestic abuse incidents or incidents of violence in a night-time economy.

Observe positive changes

Thirdly, assess whether you can observe positive changes in the behaviour or characteristics of the targets. For example, examine whether have there been fewer reported fights between rival groups. If these fights have become less frequent, assess whether there have there been changes in the number of fights in other locations – commonly known as ‘displacement’.

These measures will not provide a definitive answer about the effectiveness of an intervention but they are achievable and vital pieces of information on which you can build your homicide response strategy.

Challenges of demonstrating an intervention's impact

The procedures for assessment can be complicated and this aspect of problem solving is the basis of an entire field – evidence-based policing.

Demonstrating that an intervention actually changed something as rare as homicide is a considerable challenge. It may require years of intervention or rolling out the intervention in multiple sites.

For example, an intervention where young people at high risk of perpetrating violence were given intensive multi-systemic therapy was simulated using criminal record data. The simulation found that to detect a 25% reduction in risk of serious violent offending in this group, between 700 and 1,300 young people would need to be treated.

It may therefore be pragmatic to select other, less rare outcomes that would feasibly lead to reduced homicide in the future. For example, reductions in related forms of serious violence.

Alternatively, the integration of police records through new administrative data sets means that large multi-site collaborations are now feasible and effects of rarer outcomes may be detected. Even if a multi-site roll out is beyond your reach, police analysts are becoming increasingly skilled in evaluation and external researchers are often willing to collaborate.

Evaluating your interventions

Our policing evaluation toolkit includes evaluation design and implementation strategies. These can be used to make sure that evaluations are designed well and enable strong statements of causal impact.

The toolkit can help you to:

assess whether an intervention is effective and the strength of its impact
identify the most effective practices and guide future decisions
effectively prioritise your resources

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