The criminal justice system commonly uses predictions in sentencing, detention, and prosecutorial decisions. Uses that are exceptions to customary use include career criminal programs, pretrial preventive detention, selective incapacitation, and capital punishment decisionmaking. Short-term predictions often arise in crisis situations and involve brief deprivations of liberty. The use of predictions has been challenged on two grounds: accuracy and fairness. No prediction method is totally accurate, but predictions based on statistical evidence are more accurate than those based on intuition. In addition, restrictions on the use of predictions would prevent violations of the presumption of innocence and could actually reduce the impact of racial bias in discretionary decisionmaking. However, choosing groups for which predictions of dangerousness are to be used must be done carefully. The two crucial variables on which analysis should focus are the crime involved and the prior record. Predictions can be helpful in certain criminal justice decisions about punishment, particularly when it is recognized that the criminal justice system currently makes implicit predictions of dangerousness in many of its decisions. 16 references.