Effect of Age-at-Release on Long Term Sexual Re-offense Rates in Civilly Committed Sexual Offenders

A cohort of 136 rapists and 115 child molesters civilly committed to a prison in Massachusetts and followed for 25 years (see Prentky, Lee, Knight, & Cerce, 1997) was examined for the effect of age at time of release on sexual recidivism. The present study (1) examined the recidivism rates for each of five age-at-release groups, separately for rapists and child molesters, (2) tested the fit of linear and quadratic models for 5, 10, 15, 20, and 25-year windows using Cox regression analysis, (3) presented the predicted failure rates for rapists (up to five years post-release) and child molesters (out 21 years post-release), and (4) provided a computational formula for estimating the sexual recidivism rate given an individual's age and number of years post-release. For rapists, a linear model extending 5 years best captured our data (LR=5.62, p