The verdict in a criminal trial is a dismal medium for sending a message. Seldom does anyone outside the criminal courtroom care what has happened inside.

Even if people are paying attention, criminal jury instructions don’t ask “what message would you like to send?” but only whether the government has proven its case. A verdict that is issued to send a message is not based on the facts and the law. So a jury that has “sent a message” with its verdict has gone outside its jury instructions; a jury that has gone outside its jury instructions to reach a verdict has broken its oath. Absent compelling evidence of misconduct, we pretend that a jury followed its oath. The message of a conviction is that the government proved its case beyond a reasonable doubt; an acquittal simply means that it did not. There is no additional signal contained in the verdict.

To call for a jury to “send a message” with a culpability verdict is to call for jury nullification. Criminal-defense lawyers, of all people, know this. And yet friends of mine, experienced trial lawyers, see the verdict in George Zimmerman’s case as sending more of a message than “the Government failed to prove its case”: Black men’s lives aren’t valued, for example, or American society still thinks it’s okay to murder a Black man.

In truth, I agree with them that American society values black men’s lives less than white men’s such that black men are more likely to be killed with impunity than are white men. But that’s a message that we carry with us, not a message contained in the verdict. What my friends see as “a message” I call “confirmation bias.”

We all are affected by confirmation bias all the time: we make up our minds, and then filter our observations through our beliefs, ignoring or minimizing those that don’t confirm those beliefs and emphasizing those that do.

If George Zimmerman hadn’t expected a black kid walking through his neighborhood to be a criminal, he might have made decisions that didn’t lead to a young man’s death.

Not only do individuals do this, but juries do as well. They make up their minds early, and deprecate all evidence that doesn’t support their decisions. When you are trying a case, unless the evidence is mind-blowing, you’re going to lose if most of your jurors believe your adversary’s story at the end of opening statements. You don’t have to capture all of them: the majority on the first vote in the jury room usually sways the others to its side.

The three jurors in the Zimmerman case who voted for acquittal on the first ballot had, I would wager (though there’s no way we can know—jurors are unselfaware of their decision processes, so self-reporting can’t be trusted) gone through the whole trial “feeling” that Zimmerman had been defending himself. Which would mean, of course, that they decided the case based on something other than the law and the facts. And it may have been that six black jurors, or a more diverse panel, would have started out—and wound up—believing that Zimmerman initiated the violence.

(I believe that Martin was more likely to initiate physical violence, not because he was black but because he was seventeen. I’ve been seventeen, and I’ve been twenty-nine, and seventeen is a more volatile age. I also believe that, all else being equal, the guy who knows there’s a gun in the picture is less likely to come into striking range than the guy who doesn’t. If you’re close enough for me to hit you, you’re close enough for me to take away your gun and shoot you with it. None of that means that I think that’s what happened in the particular case.)

But we’ll never prove that the verdict would have been different with some other combination of races (defendant / complainant / jurors); it is only by circular reasoning can we say that the verdict sends a message about race.

It doesn’t tell us anything we didn’t already believe.