Predictions of Dangerousness

Long-term predictions of future dangerousness are used throughout the criminal law in investigation, pretrial detention, bail, sentencing, prison administration, parole, and early release decisions. Explicit use of such predictions by courts and legislatures is increasing. Reliance on predictions of dangerousness raises questions about the definition of dangerousness, the ethical limits on the use of such predictions, and the practical difficulties in proving dangerousness. The use of short-term predictions of dangerousness is much more widely acknowledged and accepted than the use of long-term predictions considered in this essay. Lawyers have relegated predictions of dangerousness to the psychiatric professions, leaving the moral and evidentiary issues untouched. The appropriate application of predictions of dangerousness is not a technical question of how well a prediction can be made, nor is it a question of the burden of proof required to prove elements of a criminal or civil charge. The use of predictions of dangerousness requires a political judgment balancing the risk and harm to society with the intrusion on the liberty of each member of a preventatively detained group. Not all types of prediction are equally satisfactory. Actuarial predictions are preferable to predictions that rely on an intuitive judgment by psychiatric professionals. The use of predictions of dangerousness to alter individual dispositions should be allowed only to the extent that such dispositions would be justified as deserved independent of those predictions. Within the range of punishment or control not undeserved, relative predictions of dangerousness may properly influence dispositional decisions. These principles strike a balance between individual autonomy and state authority. In the paradigm context of sentencing, the controlling principle for the use of predictions of dangerousness is that the base expectancy rate of violence for the criminal predicted as dangerous must be shown by reliable evidence to be substantially higher than the base expectancy rate of another criminal with a closely similar record, convicted of a closely similar crime, but not predicted to be unusually dangerous, before the greater dangerousness of the former may be relied on to intensify or extend his punishment.