Prediction of Crime and Recidivism

In the Protagoras, Plato states that "he who undertakes to punish with reason does not avenge himself for past offence, since he cannot make what was done as though it had not come to pass; he looks rather to the future, and aims at preventing that particular person . . . from doing wrong again" (p. 139). Twenty-four hundred years later, preventing crime by predicting who is likely to commit it and intervening in their lives to deflect the prediction is ubiquitous in the legal system. Decisions as to who should go to prison (sentencing) and when they should be let out (parole) are in substantial part predictive decisions. Assessments of the probability of future crime influence the judicial choice of whether to grant release of an offender on bail pending trial and whether to treat a juvenile as a juvenile or to waive him or her to adult court. The U.S. Supreme Court has stated that it was permissible for a state to make the imposition of the death penalty contingent upon a prediction that a murderer, unless executed, would be likely to offend again. "It is, of course, not easy to predict future behavior," Justice John Paul Stevens wrote. "The fact that such a determination is difficult, however, does not mean that it cannot be made" ( Jurek v. Texas, 428 U.S. 262 (1976)) (see Monahan and Walker for a review of caselaw in this area).

This prevention-through-prediction strategy can take the form of changing the people who are predicted to be criminal, for example, by subjecting them to treatment in order to lower the probability that they will commit a crime. Alternatively, prevention can take the form of isolating those who are predicted to be criminal by incapacitating them in an institution, so as to deprive them of potential victims. Reviewing the history of prediction in Anglo-American law, Alan Dershowitz concluded that "the preventive confinement of dangerous persons. . .who are thought likely to cause serious injury in the future has always been practiced, to some degree, by every society in history regardless of the jurisprudential rhetoric employed. . . . Moreover, it is likely that some forms of preventive confinement will continue to be practiced by every society" (p. 57).

Preventive confinement certainly is increasingly practiced in the United States. In Kansas v. Hendricks, 521 U.S. 346 (1997), the Supreme Court upheld a civil means of lengthening the detention of certain criminal offenders scheduled for release from prison. Kansas' Sexually Violent Predator Act established procedures for commitment to mental hospitals of persons who, while they do not have a "major mental disorder" (such as schizophrenia), do have a "mental abnormality" (such as, in Hendricks's case, the personality disorder of "pedophilia") which makes them "likely to engage in predatory acts of sexual violence" (p. 357). A "mental abnormality" was defined in the act as a "congenital or acquired condition affecting the emotional or volitional capacity which predisposes the person to commit sexually violent offenses in a degree constituting such person a menace to the health and safety of others" (p. 352). The Court stated:

A finding of dangerousness, standing alone, is ordinarily not a sufficient ground upon which to justify indefinite involuntary commitment. We have sustained civil commitment statutes when they have coupled proof of dangerousness with the proof of some additional factor, such as a "mental illness" or "mental abnormality." These added statutory requirements serve to limit involuntary civil confinement to those who suffer from a volitional impairment rendering them dangerous beyond their control. . . . The precommitment requirement of a "mental abnormality" or "personality disorder" is consistent with the requirements of these other statutes that we have upheld in that it narrows the class of persons eligible for confinement to those who are unable to control their dangerousness. (p. 358)

It was not until the twentieth century that attempts were made to systematize the crime prediction process. In 1928, E. W. Burgess examined the official records of several thousand former inmates of Illinois prisons and identified numerous factors, such as prior criminal record and age at release, that were associated with the commission of crime on parole. This "experience table," as he called it (which would now be termed "statistical" or "actuarial" prediction), was then used to assess the suitability of other offenders for parole release. "Thus began a criminological research tradition characterized by the production of increasingly sophisticated instruments for predicting criminal behavior. . . . Indeed, it may be said that most later work has been largely a refinement and elaboration of Burgess' basic method" (American Justice Institute, p. 7).

Prediction by means of statistical tables, however, has been only one of two approaches used in forecasting the occurrence of crime. The other approach is generally known as "clinical" prediction. This method involves experts examining an offender and rendering an opinion based upon their subjective weighing of the factors they believe relevant to the commission of future crime. Only since the 1970s have there been scientific attempts to evaluate the accuracy of clinical predictions.

This entry will selectively review the empirical literature on the prediction of criminal behavior that has been published since the report of the President's Commission on Law Enforcement and Administration of Justice in 1967. (Reviews of studies published between Burgess's work in 1928 and the report of the President's Commission can be found in Gottfredson.) This article will also place emphasis on the prediction of violent forms of criminal behavior, rather than of property offenses. First, however, it is necessary to review briefly four key concepts in predictive decision-making.