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Northwestern University Law Review

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dangerousness, police power, mental disorder


Criminal Law | Jurisprudence | Law


This article addresses the state's police power authority to deprive people of liberty based on predictions of antisocial behavior. Most conspicuously exercised against so-called "sexual predators," this authority purportedly justifies a wide array of other state interventions as well, ranging from police stops to executions. Yet there still is no general theory of preventive detention. This article is a preliminary effort in that regard. The article first surveys the various objections to preventive detention: the unreliability objection; the punishment-in-disguise objection; the legality objection; and the dehumanization objection. None of these objections justifies a complete prohibition on the state's power to detain people based on dangerousness. But they do suggest significant limitations on that power regarding acceptable methods of prediction, the nature and duration of preventive detention, the threshold conduct that can trigger such detention, and the extent to which it can replace punishment as the official response to antisocial behavior. On the latter issue, the central conclusion is that preventive detention which functions as a substitute for punishment, as in the case of sexual predator statutes, is only permissible if certain psychological and predictive criteria are met. The rest of the paper develops these criteria. It argues that the psychological criterion should be undeterrability, defined as the characteristic ignorance that one's criminal activity is criminal or a characteristic willingness to commit crime despite certain and significant punishment, a definition that differs from both the usual academic stance and the Supreme Court's inability-to-control formulation. The paper next argues that selection of a prediction criterion should be informed by two principles, the proportionality principle (which varies the legally requisite level of dangerousness with the nature and duration of the state's intervention) and the consistency principle (which takes as a reference point the implicit dangerousness assessments in the law of crimes). Finally, the paper explores some of the implications of the latter principle for the criminal law, including the possibility that some crimes - in particular various possession offenses, reckless endangerment and vagrancy - violate the fundamental norms of the police power authority.



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