In conversation, I keep accidentally referring to Zimmerman's defense lawyers as "the prosecution." Not surprising, because the defense of George Zimmerman was only a defense in the technical sense of the law. Substantively, it was a prosecution of Trayvon Martin. And in making the case that Martin was guilty in his own murder, Zimmerman's lawyers had the burden of proof on their side, as the state had to prove beyond a reasonable doubt that Martin wasn't a violent criminal.
This raises the question, who's afraid of young black men? Zimmerman's lawyers took the not-too-risky approach of assuming that white women are (the jury was six women, described by the New York Times as five white and one Latina).
"This is the person who ... attacked George Zimmerman," defense attorney Mark O'Mara said in his closing argument, holding up two pictures of Trayvon Martin, one of which showed him shirtless and looking down at the camera with a deadpan expression. He held that shirtless one up right in front of the jury for almost three minutes. "Nice kid, actually," he said, with feigned sincerity.
Going into the trial, according to one kind of analysis the female jurors were supposed to have more negative views about Zimmerman's vigilante behavior, and be more sympathetic over the loss of the child Trayvon. As a former prosecutor put it:
With the jury being all women, the defense may have a difficult time having the jurors truly understand their defense, that George Zimmerman was truly in fear for his life. Women are gentler than men by nature and don't have the instinct to confront trouble head-on.
But was the jury's race, or their gender, the issue? O'Mara's approach suggests he thought it was the intersection of the two: White women could be convinced that a young black man was dangerous.
Race and Gender
Racial biases are well documented. With regard to crime, for example, one recent controlled experiment using a video game simulation found that white college students were most likely to accidentally fire at an unarmed suspect who was a black male -- and most likely to mistakenly hold fire against armed white females. More abstractly, people generally overestimate the risk of criminal victimization they face, but whites are more likely to do so when they live in areas with more black residents.
The differences in racial attitudes between white men and women are limited. One analysis by prominent experts in racial attitudes concluded that "gender differences in racial attitudes are small, inconsistent, and limited mostly to attitudes on racial policy." However, some researchers have found white men more prone than women to accepting racist stereotypes about blacks, and the General Social Survey in 2002 found that white women were much more likely than men to describe their feelings toward African Americans positively. (In 2012, a minority of both white men and white women voted for Obama, although white men were more overwhelmingly in the Romney camp.)
What about juries? The evidence for racial bias over many studies is quite strong. For example, one 2012 study found that in two Florida counties having all-white jury pool - that is, the people from which the jury will be chosen--increased the chance that a black defendant would be convicted. Since the jury pool is randomly selected from eligible citizens, unaltered by lawyers' selections or disqualifications, the study has a clean test of the race effect. But I can't find any on the combined influence of race and gender.