"In the first six months of follow up, we found that drug court offenders were significantly less likely than the comparison group to report engaging in any criminal behavior (28 percent vs. 40 percent, p < .05); and drug court offenders averaged significantly fewer total instances of such behavior (12.8 vs. 34.1 criminal acts, p < .001). We detected additional significant differences in the prevalence of drug-related, DWI/DUI, and property-related criminal behavior.
"During the following year (the one-year period prior to the 18-month survey), the same patterns persisted. Specifically, drug court offenders were significantly less likely to engage in any criminal behavior (40 percent vs. 53 percent), drug-related crime (36 percent vs. 50 percent), DWI/DUI (19 percent vs. 27 percent), and property crime (4 percent vs. 10 percent). Among drug crimes, drug court offenders were significantly less likely to engage in both drug possession and drug sales offenses. Finally, drug court participation appeared to have a powerful impact on the total quantity of criminal activity, averaging more than 50 percent fewer criminal acts than the comparison group (43.0 vs. 88.2, p<.01); and more than 50 percent fewer drug-related crimes as well (30.6 vs. 83.1, p<.001). Of final note, both samples engaged in little violent, weapons-related, or public order offending, and differences on these latter measures were not significant."

Source

Rossman, Shelli B., et al., "Final Report, Volume 4: The Multi-Site Adult Drug Court Evaluation: The Impact of Drug Courts" (Washington, DC: Urban Institute, June 2011), p. 66.
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