Selective incapacitation and the problem of prediction

Recent innovations in sentencing policy across the United States reveal a renewed interest in the idea of selective incapacitation of criminal offenders. This is perhaps most evident in the proliferation of "Three Strikes and You're Out" habitual-offender statutes across the nation. Although the term was first introduced by David Greenberg in 1975, Peter Greenwood and Allan Abrahamse's eponymous 1982 Rand report represents the most fully articulated plan far implementing such a strategy. The report's release stimulated much discussion, because of the author's claims that selective incapacitation could simultaneously reduce crime rates and prison populations. Ethical problems inherent in such proposals as well as methodological inconsistencies in the original research warrant a reexamination of the proposal and of the empirical basis for the conclusions offered therein. Greenwood and Abrahamse's original research is replicated with a representative sample of California state prison inmates (N = 2,188) in light of these limitations, with specific focus on the methodological issues concerning the construction of the predictive scale. The selective incapacitation scheme advocated by Greenwood and Abrahamse performs extremely poorly in terms of both reliability and validity, thus precluding the implementation of such schemes. The article contains a discussion of other, more ethically acceptable uses of an instrument that identifies "high-rate" or "dangerous" offenders. In conclusion, some observations on the limitations of incarceration-based strategies of crime control are offered.