Small juries, like all small samples, carry big costs. Doesn’t a jury in a serious criminal case have 12 members? Not in Florida.
Florida is one of only two states where a jury as small as six can decide a serious felony case. It is the only state where a murder case goes to a six-member jury. And second-degree murder in Florida is serious indeed, carrying a sentence of 25 years to life. The circumstances of the shooting that killed an unarmed teenager, moreover, are sharply disputed, implicating the use of guns, the limits of self-defense and race relations. As we often do, we have given the jury in this case a challenging task.
Why should we care if the jury has six or 12 members? The Sixth Amendment guarantees the right to trial by jury, but it does not specify jury size. When the Sixth Amendment was written, was the number simply assumed? James Madison thought it was: He thought the number was 12.
For almost 200 years, the U.S. Supreme Court consistently accepted this view, defining “jury” to mean the 12-member jury. For instance, in 1930, the court said that “it is not open to question” whether juries may consist of fewer than 12.
In 1970, however, the court reversed its position in Williams v. Florida and found no constitutional objection to Florida’s six-member jury. The court labeled the general use of 12 throughout history as an “historical accident.” The court’s characterization of the historical record has been widely disputed, but even more egregiously, the court joined its new historical assessment with a strikingly inaccurate behavioral claim.
It proclaimed that the behavior of six- and 12-member juries were “functionally” equivalent, and therefore the six-member jury was unobjectionable. In fact, the overwhelming weight of empirical evidence shows that juries of six do not perform as well as juries of 12.
How do six- and 12-member juries differ? Two differences are particularly relevant in the trial of George Zimmerman. First, numerous studies of all kinds show that cutting jury size in half decreases the likelihood that the jury will reflect a representative sample of the community. The lone non-white juror on the George Zimmerman jury is just one instance of that effect. The all-female jury is another.
The gender make-up of the jury cannot be explained merely by the majority female jury pool or attorney use of challenges. A total of 10 jurors was selected, the jury of six and four alternates. Two of the alternates were male. A larger jury that included the additional four would not have been homogeneous on gender.
Ethnicity and gender are not the only dimensions of difference shortchanged by a smaller jury.
Any background or set of beliefs or life experiences that may affect reactions to the evidence is substantially less likely to be represented on a six-member jury than on a 12-member jury. Simply due to chance, unrepresentativeness is more likely when only six jurors are needed to constitute the jury. That loss is particularly troubling when the jurors are evaluating crucial and disputed evidence, like the identity of the voice in the background on the 911 tape in the Zimmerman case.
Second, jury research finds that larger juries spend more time deliberating and their discussions of testimony are more thorough than smaller juries. More vigorous debate reflects the expanded pool of abilities and perspectives provided by the larger jury. Similarly, the ability of dissenters to resist majority pressure is promoted by the increased likelihood that a dissenter whose position is not simply idiosyncratic will have one or more other jurors who share that view. The dissenters might not carry the day, but their views will be more seriously considered.
There is no evidence that jury size is associated with more pro-prosecution or more pro-defense verdicts. Thus, the key here is not that the six-member jury systematically advantages one side or the other. Rather, the point is that a serious charge demands serious procedural consideration.
Even Florida, like every other state with the death penalty, uses a 12-member jury for capital offenses. Second-degree murder does not carry the death penalty in Florida, but it does call for thorough deliberation from a variety of perspectives. The six-member jury is unnecessarily handicapped.
What should be done? Ample empirical evidence on the jury demonstrates the need to reverse course. Perhaps in the wake of the Zimmerman case, Florida will reconsider its unique position on jury size. Even better: In recent years, the Supreme Court has turned down several opportunities to revisit the question of jury size. Perhaps it should accept the next one.
Shari Seidman Diamond is the Howard J. Trienens Professor of Law at Northwestern University and a research professor at the American Bar Foundation.