In Lake County, a random sample of 104 sex offenders who were on standard probation from 1994 to July 1997 were compared to the 104 sex offenders who were enrolled in the specialized probation program in the county from July 1997 to May 1999. In DuPage County, a random sample of 110 sex offenders placed on standard probation between January 1993 and June 1996 were compared with a group of 105 offenders sentenced between July 1997 and January 2000 and placed in the specialized probation program after July 1997. In Winnebago County, a group of 105 offenders on specialized probation consisted of sex offenders sentenced between July 1997 and February 2000, along with offenders who were "grandfathered" into the specialized program. These offenders were compared to a sample of offenders who were on standard probation between June 1989 and July 1997. The specialized programs in all three counties involved close supervision of the sex offenders by probation officers trained in the special supervisory and treatment needs of sex offenders. Offenders were monitored to ensure compliance with treatment and behavioral probation conditions. The evaluation found that each county had successfully implemented a specialized sex offender probation program, but in ways distinctive to each county. The findings from the long-term impact study reflected program diversity. Generally, the evaluations found that the specialized sex offender program in each county had a positive impact on recidivism for certain groups of sex offenders and were able to detect higher rates of recidivism for groups of offenders. The counties differed in the nature of the offender groups that were most affected by the increased surveillance and other conditions of the specialized programs.