PDF - http://www.acic.org/statistics/Research/SO_Report_Final.pdf
"“The key finding is that such laws have had no systematic influence on the number of rapes committed in States with these laws. Most of the 10 States examined showed no significant difference in the average number of rapes committed before and after the passage of sex offender laws. Three of the States showed a decrease in the number of rapes after enacting such laws. One State had a statistically significant increase in the number of rapes. Based on the study’s findings and conflicting explanations of what they mean, the authors recommend that future research use cities as the unit of analysis, focus on sex offender recidivism before and after the enforcement of sex offender laws, increase the sample size, and allow for a follow-up period of at least 3 years. A literature review found little empirical evidence regarding the influence of sex offender laws; the few empirical studies that have been conducted found no significant influence of these policies on sex offender reoffending. "
