In a death-penalty case, jurors have to be willing not only to consider guilt, but willing to consider giving someone a death sentence. If a potential juror would never sentence anyone to death for any reason, he or she is disqualified, just as a juror who would always sentence a person to death would also be disqualified.

Lawyers call this part of the process of jury selection "death-qualification." Capital-defense lawyers have long argued that death-qualified juries tend to exclude more black jurors than white jurors. Research has shown that death-qualification does indeed exclude a greater proportion of black jurors than whites. But it's been only in the last few years that social scientists have found new tools to look at how death-qualification primes juries to sentence black defendants to death.

Ben Cohen, a lawyer at the Promise of Justice Initiative in Louisiana, characterizes the death-qualification process as “… the essential unfairness of the death penalty”.  He illustrates this view by explaining that the history of American racism, the death- qualification process and the death penalty are, in fact, inseparable. One of the first recorded instances of a jury made to pass a death-qualification test was in 1859, when the point was to make sure that those who were opposed to slavery and Quakers (whose religious beliefs led them to object to the death penalty in all circumstances) didn't get in the way of the execution of rebel abolitionist John Brown. In the end, Brown was found guilty of murder, treason, and conspiracy, and was subsequently hanged.

To buttress that viewpoint, Justin Levinson, a law professor and death penalty social activist at the University of Hawaii School of Law, has tried to explain why jurors, who wouldn't even be aware of their biases, might make decisions based on the automatic assumption that black lives are less valuable than white ones.
Levinson has been pioneering in this arena for some time now.  Six years ago, Levinson sat 67 students at the University of Hawaii in front of computer screens. He primed the students by asking them to sort digital images of light-skinned male faces and dark-skinned male faces into categories of "Black" or "White." Then Levinson instructed the students to hold their fingers over the "D" and "K" buttons on their keyboards, and the students sorted words like "fault," "convict," "innocent," "wrongfully accused," and "perpetrator" into the categories of "Black," "White," "Guilty," and "Not Guilty" as fast as they could.

The computers measured the students' reactions in milliseconds. The student test subjects were undergoing something called the implicit-association test (IAT), a tool social scientists have been using since the late 1990s to try to illuminate pre-conscious biases in people's brains. Other IATs had measured how people linked race to "good" and "bad" qualities, but Levinson was the first to try to see how implicit racial judgments that people may have but not even be aware that they make—might affect the presumption of innocence in a courtroom.

Not only did Levinson find that the students implicitly linked "Black" and "Guilty," he also discovered that those biases predicted how students would judge evidence as mock jurors in cases against dark-skinned defendants. But that wasn't even the strangest or most disturbing part of the University of Hawaii experiments. When Levinson asked the same students to rank the "warmth" of their feelings toward black people, the implicitly racist students actually rated friendlier feelings toward black people than the students who held less bias. 

Levinson provides an explanation to address this “anomaly” by stating that "People have come to understand that expressing racist and racially biased attitudes and stereotypes is not socially appropriate.  Social science research has established, again and again, how implicit biases are strong and pervasive."

In 2013, Levinson published a study in the NYU Law Review, analyzing how covert racism might affect sentencing in death-penalty trials in particular. He and his colleagues asked 445 jury-eligible citizens to imagine themselves as jurors studying evidence inspired by an actual case. This IAT, conducted online, measured how the race of a defendant might affect a person's judgment on the value of that person's life. This time, the test found that mock jurors associated "White" with worth and "Black" with worthless.

Death-qualified mock jurors, the ones who had answered questions about their ability to consider the death penalty and weren't excluded, had even displayed even stronger implicit and explicit racial biases than the general study sample. Stronger racial bias, Levinson found, also predicted more death sentences for black defendants when the victim was white. "The higher the level of bias on the Value of Life IAT, the more likely they were to vote for death when the defendant was black," Levinson says.  Levinson’s work strongly suggests that death-qualification "transforms” the jury.  (It shouldn’t be any surprise then, that in response, prosecutors have tried to discredit the legitimacy of the IAT despite the fact that the IAT is widely regarded as a credible scientific tool.)

But even if courts do select for implicitly racist juries, is that enough to call the practice of death-qualification unconstitutional? So far as it is known, no court has decided that issue.  It could be that the question may be regarded as too cutting-edge for the courts to take under serious consideration at this time.  

The judge makes the ultimate decision as to whether jurors can be disqualified because of their feelings about the death penalty. In that way, the death-qualification process could be read as one of the few ways judges are able to make sure a jury is fair. The quality of the judge, however, has a significant impact on the makeup of the jury.

Trying to investigate a juror's life-and-death philosophy can be a pretty circular task.  Even with a good judge, a jury might not be made up of a defendant's peers—depending on how you define "peers."   If a juror’s race is different than the race of the defendant, does the lack of insight into the racism experienced by the defendant, still make that juror a peer or not?

Ben Cohen comments that, at least, anecdotally "You can see that just by watching the death qualification-process and observing African Americans looking over at an African American defendant. They understand a history of lynching in the United States and that they're uncomfortable with the use of the death penalty. The feelings of white people tend to be the exact opposite”. 

We know that jury selection is actually a process of elimination.  In capital cases, the number of potential jurors who can be excluded for cause is much larger because anyone who is against the death penalty can be turned away.  Minorities are more likely to find problems with the death penalty for reasons as illustrated above.  And we cannot broach the subject of race during jury selection by requesting that all racists to please raise their hands.  That is simply not an option either. 
At a minimum, the courts can at least address the issues of implicit racism during the jury selection process by not glossing over the problem by pretending that “race-neutral” reasons really exist or are even close to being satisfactory.