Discretionary interventions initiated by the police, which aim to reduce future offending by diverting targeted young people away from traditional criminal justice processes.
This summary is part of the Crime Reduction Toolkit, which presents the best available research evidence on what works to reduce crime.
Focus of the intervention
Police-initiated diversion programmes provide an alternative to prosecution for young people who have previously had limited or no involvement with the criminal justice system. Young people are ‘diverted’ away the criminal justice system with the aim of reducing future offending.
Diversion can be initiated by the police at different stages of the pre-charge process, depending on the specific programme of intervention. Most commonly, alternative measures are offered or applied prior to a young person being arrested, at the point of their arrest, or prior to them being charged.
Alternatives to formal criminal justice processing can include no further action, cautions, warnings, restorative justice measures, and referrals to social, behavioural, educational or drug or alcohol treatment services.
This summary is based on one meta-analytic review that covers 19 studies on police-initiated diversion aimed at low-risk young people between the ages of 12 and 17. Of these 19 studies, 11 were based on evidence from the USA, four from Australia, two from Canada and two from the UK. The review included studies identified by January 2017.
Effect – how effective is it?
Overall, the evidence suggests that police-initiated diversion has reduced offending.
The review found that police-initiated diversion for low-risk young people resulted in a statistically significant reduction in subsequent offending compared to formal criminal justice processing. The review found that, if the reoffending rate for young people processed in the criminal justice system was 50%, the rate for young people diverted by the police to a non-criminal justice alternative was 44% – a reduction of 6 percentage points.
Across the 19 studies, 31 comparisons were made between youth diversion and formal criminal justice processing because some studies compared two or more diversion conditions to a single control condition. Eight studies found police-initiated diversion led to a statistically significant decrease in subsequent offending. 23 studies reported no evidence of an effect, while no studies found that police-initiated diversion increased subsequent offending.
How strong is the evidence?
The review was sufficiently systematic that most forms of bias that could influence the conclusions could be ruled out.
The evidence is taken from a meta-analytic review covering 19 studies. The review demonstrated a high-quality design in terms of having a transparent and well-designed search strategy, featuring a valid statistical analysis, sufficiently assessing publication bias and the risk of bias in analysis, and considering the way outcomes are measured and combined.
However, the review did not sufficiently consider the influence of statistical outliers and did not appear to use an appropriate weighting scheme to account for less rigorous study designs.
Mechanism – how does it work?
Police-initiated pre-charge diversion for young people is assumed to reduce offending by:
- reducing the exposure of young people to peer groups within the criminal justice system who may transmit negative values, attitudes or techniques or motivate offending or risky behaviour
- reducing the potential for young people to become labelled as ‘delinquent’, which might encourage young people to develop expectations for offending in the future
- providing a mechanism for forgiveness and non-stigmatisation, therefore allowing a young person to successfully reintegrate into society
- referring young people to services that may assist with the prevention of further offending or risky behaviour
However, these assumptions were not empirically tested. Future research should consider testing these potential change mechanisms.
Moderators – in which contexts does it work best?
The review found no statistically significant difference between the effects of the three typical models of diversion (that is, diversion only, diversion with referral to services, or diversion with police-initiated restorative justice). In addition, it also found no statistically significant difference in the effectiveness of interventions implemented in different countries.
Implementation – what can be said about implementing this initiative?
The review did not include detailed information on the implementation of diversion models in the included studies. However, it noted elements specific to certain models:
- Traditional police cautioning schemes included, at the minimum, a police officer, the young person in question and their parents or guardian. Victims were not involved in the process and police officers did not routinely receive training to explain the legal and social consequences of continued antisocial or criminal behaviour.
- Variants of the above scheme – such as caution plus and restorative cautioning – involved additional elements. For example, the involvement of a script to structure discussion between the young person and affected parties, and presence of the victim in the case of restorative cautioning or conferencing. A UK final warning and reprimand scheme involved an assessment-based approach evaluating the seriousness of the offence. The gravity of the offence determined whether the young person received a reprimand or final warning with referral for multi-agency assessment and placement in a behavioural treatment programme.
Economic considerations – how much might it cost?
The review did not mention the costs of police-initiated diversion for young people, and no formal economic analysis was provided.
General considerations
- Many of the primary studies were conducted several decades ago – the timeframe covered in the studies is 1973 to 2011. 13 of the 19 studies were conducted before 2000.
- Most evidence is taken from the USA, so caution should be taken when applying to other geographical contexts.
- There is limited information about the content and implementation of police-initiated diversion.
Summary
Overall, the evidence suggests that police-initiated diversion has reduced offending for low-risk young people.
Police-initiated diversion is expected to prevent young people from being labelled as 'delinquents’ or exposed to peers in the criminal system who may have otherwise encouraged offending or risky behaviour, both of which can increase the likelihood of subsequent offending.
Further research is needed to examine the implementation and economic outcomes surrounding police-initiated diversion for young people.
Reviews
Review one
Reference
Wilson DB, Brennan I and Olaghere A. (2018). ‘Police-initiated diversion for youth to prevent future delinquent behavior: A systematic review’. Campbell Systematic Reviews, 14(1), pp 1-88, https://doi.org/10.4073/csr.2018.5
Additional resources
See also, police-initiated diversion for adults.