Evaluations of COSA projects overseas have shown significant reductions in recidivism and for those reoffending, a reduction in the severity of offences. Evaluations of the pilot project in Ontario showed Circle participants had a 70% reduction in sexual reoffending compared to matched non-participants. Using a matched sample of sex offenders in Canada, Wilson (2007) found that only 2% of circle participants had reoffended sexually, compared to over 12% of non-participants. They were also almost four times less likely to reoffend violently and 3.5 times less likely to reoffend generally.
The New Zealand programme is well supported by experts. Rethinking has been able to contribute to the further development of the programme with funding from another philanthropic trust that will enable the volunteer couple to work on the project on a fulltime basis. That will in turn enable the Robson Hanan Trust to evaluate the programme from a community perspective.
Viable solutions to community violence and offending are often found within the community. COSA are an excellent example of community engagement that increases both offender accountability and community safety.