A systematic review and a meta-analysis were conducted to observe whether problem-solving court interventions employing legal supervision interventions were more effective to reduce recidivism and improve well-being outcomes for offenders compared to conventional justice processes [1]. Based on 56 independent investigations involving 11,146 treatments and 12,091 comparison subjects, the results regarding recidivism indicate that there is a statistically significant 33% reduction compared to treatment-as-usual processes. However, there was a high degree of unexplained heterogeneity among the studies investigated.
A second systematic review with a meta-analysis examined the effects of intensive probation supervision and aftercare/social reentry on juvenile recidivism [2]. Conflicting results regarding the measures were found in 27 studies. Supervision had a beneficial effect on recidivism for alleged offenders, whereas there was an adverse effect for convicted offenders (they were negatively affected).
A third study looked at experimental and quasi-experimental impact evaluations contrasting probation supervision against treatment as usual (no intervention), probing the likelihood of recidivism for offenders who had been exposed to some form of supervision [3].
While the study found an overall positive effect of probation supervision, there are some factors (the type and frequency of supervision, the skills and workload of the person in charge of supervision, and offender characteristics) that could potentially have a differential impact on recidivism rates. Despite the variety of interventions, none of them made significant use of technology to assist in the provision of supervision.