The trial of George Zimmerman, which opened with jury selection Monday, will address the legal charges against the former neighborhood watchman in the death of Trayvon Martin. But long after the jury reaches its verdict, what happened in Sanford, Fla., on the evening of Feb. 26, 2012, will continue to be litigated in living rooms, barrooms and Internet chat rooms.

That is partly because the evidence is ambiguous and only one of the two men who clashed that night is still alive, but it also reflects the fact that so many Americans have invested themselves emotionally in one of two competing narratives about what occurred.

If Zimmerman is acquitted, some of those who have called for "Justice for Trayvon" will probably continue to believe that the 17-year-old was the innocent victim of an unprovoked and racially motivated attack. If the defendant is convicted of second-degree murder or of manslaughter, some who have trumpeted his innocence will keep insisting that he acted in self-defense.

Still, most Americans will be willing to accept the outcome of the trial if it is perceived as fair not only to Zimmerman, whose liberty is at stake, but also to the memory of Martin. So far the Florida judicial system seems to be striking the proper balance, protecting the rights of the accused without allowing his lawyers to turn the proceedings into a game of "blame the victim."

Seminole County Circuit Judge Debra S. Nelson denied a request by Zimmerman's lawyer that he be allowed to refer in his opening statement to Martin's use of marijuana, his history of fighting or his suspension from high school. But she left open the possibility that some character evidence might be admissible later in the trial. For example, if the prosecution were to argue that Martin was a habitually reserved and retiring personality, the defense might at that point be able to use some of the currently prohibited information to contradict that assertion. But the judge should be vigilant about allowing Zimmerman's attorney to shift the focus to Martin's personal failings.

It is also vital that the jury selection process be meticulous in screening out candidates who are unable to put aside preconceptions about either Zimmerman or Martin. The death of Martin was a tragedy, and the initial hesitation of authorities to pursue the case unpardonable. But whether Zimmerman is guilty as charged is a question that must be answered on the basis of the evidence about what occurred that night, not on irrelevant characteristics of either the defendant or the deceased.