See criticism of this study by R. Hanson.
Recidivism risk is an important component of criminal justice and correctional planning, especially when it comes to sex offenders who may pose physical danger to others. The current study assessed the recidivism rate of 320 sex offenders and 31 violent non-sex offenders over a 25 year follow-up period.
Participants were sex offenders referred for psychiatric treatment by the court, police, probation services, defense lawyers, or mental health professionals between 1966 and 1974. The comparison group was comprised of the 31 violent non-sex offenders. Recidivism data were drawn in 1994 and 1999 from the RCMP database and from hospital records (Civil commitment patients. Accordingly, results not to be applied to all sex offenders. eAdvocate see other criticisms below]).
Results of statistical analyses indicated that approximately 3 out of 5 sex offenders were re-convicted of a sexual offense during the 25 year follow-up. When all offenses were considered, including non-sex offenses, four out of five sex offenders recidivated during the follow-up period.
Child sexual abusers and exhibitionists were most likely to re-offend, while incest offenders were the least likely to re-offend. The findings reveal that sex offense recidivism remains a problem over a significant part of a sex offender’s adult life.
Correctional planning for sex offenders should include actuarial measures of risk, although they should be used with caution until more long-term studies of recidivism risk among this population can be carried out. Tables, notes, references ..Source.. by Ron Langevin ; Suzanne Curnoe ; Paul Fedoroff ; Renee Bennett ; Mara Langevin ; Cheryl Peever ; Rick Pettica ; Shameen Sandhu ---- Full copy here
A sample of 320 sex offenders and 31 violent non-sex offenders, seen for psychiatric assessment between 1966 and 1974, were compared retrospectively on lifetime recidivism rates to 1999 over a minimum of 25 years.
A number of criteria and data sources were used; RCMP records and hospital records were the best sources, albeit the RCMP had records for only 54.1% of the cases. Approximately three in five offenders reoffended, using sex reoffence charges or convictions or court appearances as criteria, but this proportion increased to more than four in five when all offences and undetected sex crimes were included in the analysis.
Group differences in recidivism were noteworthy, with child sexual abusers and exhibitionists most likely to reoffend and incest offenders least likely. Time at large and time incarcerated played a relatively minor role overall in results, except in the case of offenders who were sexually aggressive against adult females, courtship disordered, or violent.
The typical known criminal career spanned almost two decades, indicating that sex offence recidivism remained a problem over a significant part of the offenders' adult lives.
Myth: Sex offenders have a 94 percent recidivism rate
Proponents of tough sanctions against sex offenders often cite a Canadian study published in 2004, “Lifetime Sex Offender Recidivism: A 25 year Follow-Up Study,” led by Canadian researcher Ron Langevin. The authors looked at 320 Canadian sex offenders referred to a single clinic for psychiatric evaluations between 1966 and 1974, when treatment programs for this group were uncommon. The report used an unusual definition of a recidivist as someone who had committed two or more sex crimes in their lifetime, even crimes they did before researchers began to follow them.
Langevin reported a 61.1 percent sex crime recidivism rate, including 51.1 percent for incest. The researchers also tabulated confessions the offenders made during counseling and new arrests that failed to bring convictions. Adding those presumed crimes to actual convictions increased the overall sexual recidivism rate to 88.3 percent, including 84.2 percent for incest. Measured this way, molesters of young children outside their own family had an even higher rate, 94.1 sex crime recidivism over 25 years. To this writer’s knowledge, that is the highest reported rate in any of the hundreds of existing recidivism studies. It underlies much of the widespread belief that all sex offenders are incurable and unrepentant.
Critics of Langevin claim his cohort was the worst of the worst offenders. Canadian researcher Karl Hanson has called it a nonrandom sample chosen for evaluations in connection with major prosecutions, civil commitment proceedings or insanity defense cases. This group also came under scrutiny in a different era when sex offender treatment programs were rare and experimental. The ensuing revolution in child protection and sex abuse prosecution over half a century has swollen American prison populations of sex offenders by fifty- and a hundred-fold. The group in prison now is arguably less prone to recidivism than members of the Langevin study.
Canadian researcher Cheryl Webster and colleagues have called the Langevin study so flawed it lacks any scientific integrity. In a rebuttal entitled “Results by Design: The Artefactual Construction of High Recidivism Rates for Sex Offenders,” Webster said more than half the individuals in the sample were already recidivists by Langevin’s definition at the time of their evaluations, thus ensuring at least a 50 percent recidivism rate. In the rest of the literature on criminology and in the popular press, recidivism generally means a new crime committed after release from prison.
Webster noted the Langevin sample was much larger at first. His team removed any people from the study whose criminal records had been lost or purged from the justice system after 15 years for lack of new crimes or charges. In effect, the scientists deleted most of the non-recidivists and thereby skewed the recidivism rate. In a reply to his critics, Langevin cautioned against making claims about all sex offenders based on this sample. He defended his definition of recidivism as one of many legitimate ways to measure it.
Those promoting tough sex offender laws rely as well on a 1997 study led by Robert Prentky. His group looked at 136 rapists and 115 child molesters released from the Bridgewater sex offender civil commitment center in Massachusetts between 1959 and 1986. The sexual recidivism rates based on new sexual charges were 32 percent for molesters and 25 percent for rapists. But the length of time the men were free in the community varied widely. If all had been at large the full 25 years covered in the study, the authors estimated the sexual recidivism rates would have been 52 percent for molesters and 39 percent for rapists.
This research dates from the same period as the Langevin findings and looked at a narrow sample of men already adjudicated to be an acute risk to reoffend. The average rapist had 2.5 sex crimes on his record before the crime that sent him to Bridgewater. The child molesters averaged 3.6 sex offenses prior to the crime that triggered civil commitment. Using Lengevin’s method, the recidivism rates for both groups would have been nearly 100 percent. The Prentky researchers concluded, “The obvious, marked heterogeneity of sexual offenders precludes automatic generalization of the rates reported here to other samples.” ..Source..