Preventing future offending of delinquents and offenders: what have we learned from experiments and meta-analyses?

Objectives The main aim of this article is to review knowledge about what works in preventing future offending by delinquents and offenders. We examine what has been learned from randomized controlled trials (RCTs), systematic reviews, and meta-analyses in the past 10 years about the effectiveness of correctional interventions. We focus on important recent RCTs, systematic reviews, and meta-analyses from 2005 onwards. Where reported in the meta-analyses, we examine the number of RCTs included in the analyses and whether results from experiments differ from those contained in non-experimental designs. Interventions based on surveillance, control, deterrence, or discipline are ineffective. Interventions based on restorative methods and skills training are effective. The effectiveness of interventions providing services and opportunities is unclear. More randomized trials are needed to evaluate the effectiveness of programs. Only evidence-based programs should be implemented.