Reducing Repeat Offending Through Less Prosecution in Victoria, Australia: Opportunities for Increased Diversion of Offenders

Cambridge Journal of Evidence-Based Policing (2019) 3:109–117 https://doi.org/10.1007/s41887-019-00040-0 ORIGINAL ARTICLE Open Access Reducing Repeat Offending Through Less Prosecution in Victoria, Australia: Opportunities for Increased Diversion of Offenders David Cowan, et al. [full author details at the end of the article] Published online: 7 November 2019 # The Author(s) 2019 Abstract Research Question How did the use of diversion from prosecution and criminal sentencing change in Victoria, Australia, in the 10 years to 2016/2017, with what estimated effects on repeat offending? Data We tracked 1,163,113 criminal cases brought against both juveniles and adults by police in the state of Victoria, Australia, including 181,836 diversions, during the 10year time period from the fiscal year of 2007/2008 through 2016/2017. Methods Taking the percentage of all cases diverted in the first year (25.6%), we calculated for each of the study years how many more cases would have been diverted from prosecution across the subsequent 9 years if the diversion rate had stayed the same (“missed opportunities”). We multiplied the estimated number of these “missed opportunities” by the reduced frequency of repeat offences that the prosecuted offenders were likely to have committed, after adjusting for the time at risk by the number of years left in the study period. Then, based on a systematic review of diversion experiments (Petrosino et al. 2010), we applied the standardised effect size of diversion in those studies to Farrington’s (1992) annualised crime frequency per 100 offenders aged 25, multiplying that effect across all of the person-years after a case was prosecuted rather than diverted, using both population-based rates and rates based only on detected offenders at that age. Findings The diversion rate in Victoria dropped in half over 10 years, from 25.6% to 12.5%. The total missed opportunities for diversion, compared to the counterfactual of applying diversion at a constant rate of 25% over that time period, totalled 115,885 cases over the 10 years. Taking an average effect size (d = − 0.232) across seven experiments with a mean follow-up time of 12–13 months, as derived from a systematic review of diversion experiment outcomes, our illustrative estimate is that at least 8 crimes per year per 100 offenders could have been prevented among the missed opportunity cases. Using a population rate of offending, the estimate equals 1474 crimes that could have been prevented. Using the offending population rate, we estimate that 37,050 offences could have been prevented. Conclusions While the exact amount of crime prevented remains speculative, the application of best evidence to the missed opportunity cases suggests that more diversion could have resulted in substantially less repeat offending, and hence less total crime. 110 Cambridge Journal of Evidence-Based Policing (2019) 3:109–117 Keywords Arrest . Prosecution . Diversion . Prevention . Juveniles . Recidivism Introduction The decision not to prosecute in the public interest is a long-standing power of the constable. The decision to work out an informal resolution between the offender and the victim, “outside the King’s justice,” has centuries of precedent. The simple view that “police investigate” and “courts decide” is manifestly inaccurate (Sherman and Neyround 2012; Slothower et al. 2015). As UK Attorney General Sir Hartley Shawcross said in 1951, “it has never been the rule in this country, and I hope it never will be, that suspected criminal offences must automatically be the subject of prosecution” (House of Commons Debates 1951). He went on to outline the importance of public interest considerations having regard to the circumstances of offending. In Australia, the current Victorian Prosecutorial Guidelines (Office of Public Prosecutions 2018) contain such a consideration, whereby the prosecution may only proceed if it is in the public interest to do so. As Petrosino et al. (2010) observe, police have tremendous discretion on how to handle offenders and can decide whether they should be officially processed by the justice system or diverted from it. They offer strong empirical evidence that these police decisions about diversion can prevent or cause crime for years to come. Police use of diversion affects not only offenders. It also affects victims, police resources and the costs of the criminal justice system (Neyroud 2018). Any changes to criminal justice processing and police practices yield large ripple effects. For police or government to change policy, the evidence that an approach works should be clear (Laycock and Mallender 2015), especially in the precise ways it has been tested. Although diversion offers the possibility of great benefits if implemented well, if implemented poorly, diversion can present a range of risks (Slothower 2014). The use of diversion is often subject to debate for both technical and “social climate” reasons. This article provides a case study of changing diversion practices in a context of social reactions to perceptions of rising crime and major increases in the number of police officers. It documents the trends in reduced use of diversion per 100 offenders. It also estimates the number of crimes that could have been prevented had the diversion rate not been reduced, based on an international systematic review (including Australian studies) of the effects of diverting juveniles from prosecution. Diversion in Victoria, Australia Diversion as a criminal justice policy has been a highly contested issue in the Australian state of Victoria in recent years, where the entire criminal justice system has been under increasing pressure. An additional 1700 police had been deployed as of 2015, and 3135 more were planned to be deployed over the subsequent 4 years (Victorian Government 2017). Weekend courts have been introduced, 18 new magistrates assigned and 98 million dollars earmarked for additional police prosecutors, all as a direct result of the increasing demands on the criminal justice system. Over the Cambridge Journal of Evidence-Based Policing (2019) 3:109–117 111 decade ending in 2017, the prisoner population in Victoria has increased by 71% (Justice and Regulation 2017). Little discussion, however, has addressed the question of whether research evidence supports the effectiveness of a rapid increase in prosecutions and imprisonment in order to reduce crime or at least repeat offending. If there are alternative responses that may be more effective in reducing crime, they would logically deserve consideration. Given the evidence of the most recent systematic review on diversion, as well as other sources, diversion may produce less crime than prosecution. The intention of this study, therefore, is to track Victorian data for opportunities to target more police diversion for crime prevention. If such targets can be identified, they could constitute opportunities to relieve t (...truncated)