Death Qualification of Juries

Death qualification is a unique form of jury selection that is used only in capital cases. Potential jurors are screened beforehand on the basis of their attitudes toward death penalty, and persons holding “disqualifying” attitudes or beliefs about capital punishment are dismissed from further participation. In the late 1960s, the U.S. Supreme Court established the standard by which prospective jurors could be constitutionally excluded from service on a capital jury as one of “unequivocal opposition” (i.e., if the prospective juror said that he or she could never impose the death penalty no matter what the facts or circumstances of the case). Since then, the process of death qualification has been the subject of extensive legal commentary and social science research, as well as the focus of a number of constitutional challenges and revisions in the legal standard of exclusion itself.

The Nature and Effect of Death Qualification

In modern death penalty jurisprudence, all capital trials are bifurcated. If a capital defendant is convicted of a crime for which the death penalty is a possible punishment (first-degree murder plus some special circumstance or feature that is found to be present in the case), a second sentencing or penalty phase of the trial is held. In this phase, the capital jury decides whether to sentence the defendant to death or some lesser punishment (typically life in prison without possibility of parole). To accommodate the state’s interest in having only those jurors serve who can consider imposing the death penalty in the second part of the capital trial, should one occur, the law permits the screening of all potential jurors on the basis of their death penalty views. However, this selection or screening process transpires at the very outset of the trial, before any evidence has been presented and, perforce, before the actual jury has decided whether the defendant is guilty or not. Because it occurs so early in the trial, death qualification may have a significant impact on all of the jury’s subsequent decision making.

In fact, social science research has established the fact that death-qualified juries are significantly different from non-death-qualified juries in a number of important ways. For one, death qualification produces juries that are less representative than non-death-qualified juries. That is, because women and minorities (especially African Americans) are more likely to oppose the death penalty, they are more likely to be excluded from death-qualified juries. Also, because attitudes toward the death penalty tend to be correlated with other attitudes about the criminal justice system, researchers have found that death qualification produces juries that hold a more homogeneous perspective than other juries, where attitudinal diversity would be more likely to occur. Among other things, death-qualified juries are generally more favorable to the perspectives of prosecutors and law enforcement, more susceptible to things such as potentially prejudicial pretrial publicity and aggravating evidence that may be introduced at trial, and simultaneously more oriented toward “crime control” goals and less committed to “due process” values.

Perhaps not surprisingly—given the way death qualification skews the composition of the group deemed eligible to serve, death-qualified juries also tend to be “conviction prone.” That is, based on the same set of case facts and circumstances, research shows that they are more likely to find a defendant guilty than are non-death-qualified juries. Of course, because they are selected precisely on the basis of their willingness to impose the death penalty, they also are “death prone”— that is, they are more likely to render death verdicts than a non-death-qualified jury would be.

In addition, research has shown that the process of death qualification itself produces biasing effects among persons exposed to it. That is, because it requires jurors to consider the issues that would be germane only after they had found the defendant guilty (e.g., whether they actually could impose the death penalty) and to commit themselves to a course of action that would occur only in the sentencing phase of the trial (i.e., pledge to consider all punishment options, including the death penalty)—before any evidence has been presented, the process of death qualification itself appears to increase prospective jurors’ belief in the defendant’s likely guilt. The nature of the questioning that occurs during death qualification also has the potential to desensitize jurors to the issue of imposing the death penalty, to lead some jurors to believe that they have committed themselves to actually imposing the death penalty if they find the defendant guilty, and to imply that death penalty imposition is the legally approved sanction in the penalty trial of their case. Obviously, these process-related biases occur in addition to the effects that death qualification has on the composition of the capital jury.

There is one additional aspect of death qualification that continues to have legal and social scientific significance. The process of excluding potential jurors from participation in capital trials solely on the basis of their feelings about the death penalty has implications for an important legal judgment that courts make about the scope of death penalty support in the United States. In particular, as Justice John Paul Stevens and others have acknowledged, one of the key “societal factors” that the U.S. Supreme Court has continued to look to “in determining the acceptability of capital punishment to the American sensibility is the behavior of juries” (Thompson v. Oklahoma, 1988, p. 831). Thus, the behavior of capital juries, each one of which has been created through a process that includes death qualification, continues to serve as a measure of the “national consensus” on the death penalty and an important index of the extent to which certain death penalty laws offend evolving standards of decency, the hallmark of an Eighth Amendment analysis. However, because death-qualified juries are selected precisely on the basis of their willingness to actually impose the death penalty, and therefore differ from non-death-qualified jurors on this dimension (as well as many others), their death-sentencing behavior is unlikely to be representative or reflective of the true “American sensibility” with respect to capital punishment.

Legal Challenges to Death Qualification

Social science research documenting the range of biasing effects produced by death qualification has served as the basis for a number of constitutional challenges arguing that the unrepresentative and conviction-prone nature of the capital jury compromises the fair trial rights of capital defendants. In one of the first of these cases, the U.S. Supreme Court raised the threshold of legal exclusion from one of mere “scruples” against the death penalty (which had been the operative death qualification standard for more than 100 years) to “unequivocal opposition”—a belief strong enough to preclude the juror from ever returning a death verdict. (See Witherspoon v. Illinois, 1968.) However, the social science data offered in support of the petitioner’s claim that death qualification was unconstitutional were deemed too “tentative and fragmentary” to support such a ruling.

A little more than a decade later, a major challenge to death qualification was lodged in California. It relied on a large body of more recently assembled social science data and was based on state constitutional grounds. Although the state Supreme Court cited and discussed the numerous social scientific studies that were introduced in an evidentiary hearing in the case, the court stopped short of prohibiting death qualification, at least as it was practiced in California. However, the court did seek to minimize the biasing effects of the process of death qualification itself by requiring that it be conducted on an individual, sequestered basis (to minimize the extent to which any one juror was repeatedly exposed to it; see Hovey v. Superior Court, 1980).

In Lockhart v. McCree (1986), the U.S. Supreme Court rejected a federal constitutional challenge that was based on many of the same studies that had been introduced in the California case. The Court questioned the validity of the relevant social science research, noting that none of the studies was methodologically perfect and, of course, could entirely re-create the “felt responsibility” of an actual capital jury. In addition, however, the Court ruled that, even if valid, the research was not dispositive since juries biased in the ways that death-qualified juries appeared to be could have arisen by chance. Specifically, Justice Rehnquist wrote for the majority that “it is hard for us to understand the logic of the argument that a given jury is unconstitutionally partial when it results from a State-ordained process, yet impartial when exactly the same jury results from mere chance” (p. 178).

Changes in the Legal Standard of Exclusion

The legal standard that is used in the death qualification process has changed several times. As noted earlier, in 1968, the U.S. Supreme Court modified the operative standard that had been in use for more than a century. In addition, however, some 17 years after this decision, the Supreme Court again revised the threshold for excluding jurors from participation in capital cases—this time broadening it from unequivocal opposition to merely holding death penalty attitudes that would “prevent or substantially impair the performance of his [or her] duties as a juror in accordance with his [or her] instructions and oath” (Wainwright v. Witt, 1985, p. 852). The significance of the Witt opinion was acknowledged by legal practitioners and scholars alike, who suggested that the less precise language and seemingly broader scope of the Witt formulation would result in a substantial increase in the size of the excludable group as well as complicate the precise application of the legal standard of exclusion.

Finally, the death qualification standard underwent yet another doctrinal change in 1992, when the U.S. Supreme Court ruled that persons whose support of the death penalty is so strong that it would “prevent or substantially impair” the performance of their duties (sometimes called “automatic death penalty” or “ADP” jurors) also should be legally disqualified from serving in capital cases. (See Morgan v. Illinois, 1992.) Thus, “modern” death qualification now operates to exclude persons whose death penalty attitudes would merely “impair” the performance of their functions in a capital trial, and it eliminates persons on the basis of both support for as well as opposition to extreme death penalty. In practical terms, the intended “balancing” of the standard of exclusion (by including extreme death penalty supporters as well as opponents) does not seem to have significantly altered the biasing effects brought about by death qualification. Scholars and practitioners acknowledge that extreme death penalty supporters are not as readily identified as the comparable group of death penalty opponents. As a result, death-qualified juries continue to suffer from many of the biases identified in the earlier research and relied on as the basis for constitutional challenges (albeit, in some jurisdictions, on an attenuated basis).


  1. Allen, M., Mabry, E., & McKelton, D. (2004). The impact of juror attitudes about the death penalty on juror evaluations of guilt and punishment. Law and Human Behavior, 22, 715-731.
  2. Bersoff, D. (1987). Social science data and the Supreme Court: Lockhart as a case in point. The American Psychologist, 42, 52-58.
  3. Haney, C. (Ed.). (1984). Death qualification [Special issue]. Law and Human Behavior, 8.
  4. Haney, C., Hurtado, A., & Vega, L. (1994). “Modern” death qualification: New data on its biasing effects. Law and Human Behavior, 18, 619-633.
  5. Hovey v. Superior Court, 28 Cal. 3d 1 (1980).
  6. Lockhart v. McCree, 476 U.S. 162 (1986).
  7. Morgan v. Illinois, 504 U.S. 719 (1992).
  8. Thompson, W. (1989). Death qualification after Wainwright v. Witt and Lockhart v. McCree. Law and Human Behavior, 13, 185-215.
  9. Thompson v. Oklahoma, 487 U.S. 815 (1988).
  10. Wainwright v. Witt, 469 U.S. 412 (1985).
  11. Witherspoon v. Illinois, 389 U.S. 1035 (1968).

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