How hard can judges crack down on bias?

A Louisiana death-row inmate is asking the US Supreme Court to throw out his murder conviction because the prosecutor in his 1996 trial excluded all African-Americans from the jury – and then compared the defendant to O.J. Simpson during closing arguments.

The inmate's lawyers say the O.J. Simpson reference was intended to racially inflame the all-white jury into sentencing a black defendant to death.

On Tuesday, the high court takes up the Louisiana case to examine the prosecutor's actions and determine whether the courts in Louisiana were aggressive enough in rooting out alleged racial bias in jury selection.

"The record doesn't fully convey the reality of Jefferson Parish and of this prosecutor," says the inmate's lawyer, Stephen Bright of the Southern Center for Human Rights in Atlanta.

He says the prosecutor displayed a toy electric chair in his office with five picture cutouts of each individual he had sent to death row. All were black. "This was a cowboy prosecutor in an office that was run kind of like a frat house," Mr. Bright says. "Striking all the blacks from the jury was business as usual in that office."

The Jefferson Parish District Attorney's Office defends the prosecutor's conduct, saying race played no role in jury selection or in the O.J. Simpson comments. The Louisiana Supreme Court has twice reached the same conclusion.

The US Supreme Court has ruled that race cannot be a factor in excluding someone from jury service. Both sides in a trial work hard to select a panel they believe will be open to their perspective. Amid this competition for sympathetic jurors, it is difficult – and in some cases, impossible – for trial judges to identify whether it is race or a legitimate factor behind a decision to exclude a prospective juror.

The case at hand, Snyder v. Louisiana, presents the high court with an opportunity to clarify how judges are to go about policing the issue.

Allen Snyder was convicted of attacking his estranged wife and a man she was dating. The man was killed in the 1995 knife attack.

The prosecutor in the case, James Williams, drew comparisons both before and during the trial to the O.J. Simpson case. The retired football star was accused of stalking and killing his estranged wife and a male companion. Mr. Simpson's acquittal in 1995 exposed a deep racial divide in the country, with most African-Americans celebrating the verdict as rare justice for a black man, and most whites believing Simpson got away with murder.

In the appeal to the Supreme Court, Mr. Snyder's lawyer says the prosecutor intentionally excluded all five prospective black jurors to create a whites-only panel. That action set the stage, he says, for the prosecutor's later reference to Simpson during closing arguments.

"[The prosecutor] knew that by selecting an all-white jury there was a likelihood that his appeal to race would play on the resentments [lingering from the Simpson acquittal] of at least some members of the jury," Bright says in his brief to the court.

The Jefferson Parish District Attorney's Office rejects allegations that race played any part in the case. Each of the black jurors was excused from the panel for reasons unrelated to race, Assistant District Attorney Terry Boudreaux says in its brief to the court. And Simpson was a legitimate topic of public discussion, he says.

"The O.J. Simpson case was an historical fact of which the jury would have been aware," Mr. Boudreaux writes in his brief. "The mentioning of it was no more than pointing out some obvious similarities between the two cases: a husband upset over his wife's perceived relations with someone else, a furious attack of his wife while in the company of another man, the attacks result in death, the attacks are with knives.…"

Other analysts disagree. "The prosecutor's premeditated strategy of purging one racial group and appealing to the racial biases of another was constitutionally intolerable," says Sherri Johnson in a friend-of-the-court brief filed by the Cornell Death Penalty Project.

Former US Solicitor General Seth Waxman, now a lawyer in Washington, has called the prosecutor's actions unusual, unethical, and unconstitutional. "The prosecutor's comparisons to O.J. Simpson were manifestly an attempt to divert the jury from its duty to render a verdict according to the evidence and the law," Mr. Waxman writes in a friend-of-the-court brief filed on behalf of the Constitution Project.

There is no question of Snyder's guilt. His lawyer concedes in his brief that Snyder was clearly responsible for the death. But he seeks a new trial because he says a new jury, more representative of the entire community in Jefferson Parish, might find Snyder guilty of a lesser offense than capital murder. And even if they convict Snyder again of capital murder, he says, a different jury might opt for life in prison rather than death.

At the time of the attack, Snyder was depressed and distraught over his disintegrating marriage. He held a steady job, was a four-year Marine Corps veteran, and did not have an extensive criminal background. After the attack, police found him barricaded in his house, curled up in the fetal position, repeating: "They're coming to get me. They're coming to get me."

Mr. Williams, the prosecutor, made his first reference to Simpson in pretrial comments to the media. He called the Snyder case his "O.J. Simpson case."

Snyder's lawyer filed a pretrial motion, calling such comments "prejudicial and racially inflammatory." But the trial judge declined to order the prosecutor to stop after Williams promised not to mention Simpson in the trial. Despite his pledge, Simpson came up in Williams's closing argument.

Snyder's lawyer told the jurors during his own closing argument how Snyder had called police and told them he was going to kill himself.

Williams seized on the issue in a rebuttal argument, saying the episode reminded him of the "most famous murder case … in probably recorded history…."

Snyder's lawyer immediately objected, but the judge allowed the prosecutor to continue.

"The most famous murder case, and all of you all have heard about it, happened in California very, very, very, similar to this case," Williams told the jury. "The perpetrator in that case claimed that he was going to kill himself as he drove in a Ford Bronco and kept the police off him, and you know what, he got away with it."

Although he did not mention Simpson by name, analysts say the reference was clear, including emphasizing that Simpson "got away with it."

After the jury sentenced Snyder to death, defense lawyers asked for a new trial. The trial judge and the Louisiana Supreme Court have twice upheld the conviction.

The US Supreme Court is expected to rule by June.