Courts commonly excluded anyone who opposed the death penalty in any manner until the 1968 landmark decision by the U.S. Supreme Court in Witherspoon v. Illinois which held that the death qualification, if it was to continue at all, must be greatly curtailed and left open the question of death-qualified juries' proneness to convict. Empirical studies supported the proposition that death-qualified juries are more likely to favor the prosecution and more prone to convict than ordinary juries, but courts continued to find this evidence insufficient in the 1970's. In 1978, the National Jury Project sponsored three major studies which demonstrated that death-qualified jurors compared to nonexcluded jurors were more likely to believe in strict law enforcement, distrust the defense attorney more than the prosecutor, and to believe the prosecution's version of conflicting testimony. More women than men and blacks than whites were excluded from jury service by death qualification. Trial simulations supported the hypothesis that the very process of death qualification prejudiced jurors against the defendant. These studies were used as evidence first in People v. Moore (1979), where the motion was denied, and then in Hovey v. the Superior Court. The Hovey decision endorsed the studies' findings, but concluded that it needed additional scientific research on a related aspect of capital jury selection before reaching an ultimate conclusion on the constitutionality of death qualifications. The paper discusses two recent appellate decisions on death qualifications and outlines strategies for making a pretrial motion to limit death qualification, limiting the adverse consequences of death qualifications, and conducting an effective death-qualifying voir dire. The article includes 34 footnotes.