Empirical arguments made to the Court in Barefoot v. Estelle and McCleskey v. Kemp are examined in detail. In both cases the Court rejected the data-oriented positions. In Barefoot, the Court rejected psychiatric statistical studies predicting future violence in the defendant. In McCleskey, a defendant presented statistical evidence indicating that defendants charged with killing whites were more likely to receive the death penalty than were those charged with killing blacks. A majority of the Court rejected the application of the statistical evidence to the specifics of the defendant's case. Justice Blackmun dissented from the majority in both cases and demonstrated an awareness of the validity of empirical data arguments. Statistical consultants should be employed to help the Court interpret empirical data arguments. 51 footnotes.