Is The Supreme Court Relying On False Data On Sex Offender Recidivism?

Adam Liptak has a fascinating article out this week on the lack of foundation for a statistic that has been heard in the Supreme Court like a virtual manta:  that sex offenders have an 80 percent high rate of recidivism.  Liptak. however, has researched the source of that statistic and found that it is based on the most casual and unreliable reference from a 1988 book.

Liptak noted that the “high rate of recidivism” of sex offenders was referenced last week and that the Court has repeatedly relied on the 80 percent figure.  He then noted

But there is vanishingly little evidence for the Supreme Court’s assertion that convicted sex offenders commit new offenses at very high rates. The story behind the notion, it turns out, starts with a throwaway line in a glossy magazine.

Justice Anthony M. Kennedy indicated the source of the statistic fromMcKune v. Lile. It was a reference to “A Practitioner’s Guide to Treating the Incarcerated Male Sex Offender,” published in 1988 by the Justice Department.  The 231 page book however has lower cited rates of recidivism and “[o]nly one source claimed an 80 percent rate, and the guide itself said that number might be exaggerated.”

The Court may then have simply repeated the “fact” until it is now a virtual touchstone of every argument and opinion supporting sentencing rules.  It could be an example of legal mythology becoming legal fact.