"Overall, results indicate that heroin prescription is a very promising approach in reducing any type of drug related crime across all relevant groups analyzed. It affects property crime as well as drug dealing and even use/possession of drugs other than heroin. These results suggest that heroin maintenance does not only have an impact by reducing the acquisitive pressure of treated patients, but also seems to have a broader effect on their entire life-style by stabilizing their daily routine through the commitment to attend the prescription center twice or three times a day, by giving them the opportunity for psychosocial support, and by keeping them away from open drug scenes."

Source

Ribeaud, D. (2004). Long-term Impacts of the Swiss Heroin Prescription Trials on Crime of Treated Heroin Users. Journal of Drug Issues, 34(1), 163–194. doi.org/10.1177/002204260403400108