New York Times

WASHINGTON — “We have an arsenal of smoking guns,” a lawyer for a death row inmate told the Supreme Court on Monday.

The justices were considering a case on race discrimination in jury selection, and there seemed to be consensus that prosecutors in Georgia had crossed a constitutional line in 1987 in their efforts to exclude all blacks from a jury that would hear a capital case against a black man, Timothy T. Foster, who was accused of killing a white woman, Queen Madge White.

Prosecutors used peremptory challenges — ones that do not require giving a reason — to exclude every potential black juror.

In 1986, in Batson v. Kentucky, the Supreme Court made an exception to the centuries-old rule that peremptory challenges are completely discretionary. It ruled that race discrimination in jury selection was unconstitutional and required lawyers accused of it to provide a nondiscriminatory explanation.

Such challenges are rare, and most lawyers are capable of offering reasons unrelated to race. Many legal experts say the Batson ruling has turned out to be toothless and symbolic. But Monday’s case, Foster v. Chatman, No. 14-8349, appeared poised to be an exception.

“Isn’t this as clear a Batson violation as this court is likely to see?” Justice Elena Kagan asked.

The case certainly had unusually vivid evidence. In notes that did not surface until decades after the trial, the result of a public records request, prosecutors had marked the names of black prospective jurors with a B and highlighted those names in green.

They circled the word “black” where potential jurors had noted their race on questionnaires. They ranked the black prospective jurors in case “it comes down to having to pick one of the black jurors,” as the prosecution’s investigator put it in a draft affidavit at the time.

In the end, prosecutors struck all four black potential jurors.

When challenged, Stephen Lanier, the lead prosecutor, denied that race had been a factor and offered other reasons for the strikes. The black prospective jurors were confused, incoherent, hostile, disrespectful or nervous, he said, and three did not make enough eye contact.

“All I have to do is have a race-neutral reason,” Mr. Lanier said at the time, “and all of these reasons that I have given the court are racially neutral.” The judge rejected the defense’s objection.

The Supreme Court’s more conservative members mostly discussed potential hurdles in the case. Justice Antonin Scalia, for instance, said the trial judge was in the best position to assess the prosecutors’ intent. “It’s sort of hard for us to do it on a cold record,” he said.

Justice Kagan agreed but added that this was “a case where all the evidence of intentional discrimination was not before the judge at the time.”

Justice Samuel A. Alito Jr. appeared troubled by some explanations offered by prosecutors that seemed to be at odds with the facts.

A 34-year-old black woman, for instance, was said to be too close in age to the defendant, who was 19. (The prosecution did not challenge eight prospective white jurors age 35 or under.)

Beth A. Burton, a lawyer representing the State of Georgia, said prosecutors had noted the jurors’ races and marshaled long lists of race-neutral explanations because the Batson decision had just been issued and they were unsure how to comply with it.

Justice Stephen G. Breyer asked whether Mr. Lanier or the state had ever said such a thing at the time or in the decades before the case arrived at the Supreme Court. Ms. Burton said no.

Justice Breyer underscored the concession. “So if that had been his real reason, isn’t it a little surprising that he never thought of it, or didn’t tell anybody, until you raise this argument in your main brief?” Justice Breyer asked.

Justice Anthony M. Kennedy asked how courts should assess the “laundry list of reasons for striking the black jurors” when “some of those are reasonable and some are implausible.”

Stephen B. Bright, a lawyer for Mr. Foster, said courts should be wary of encouraging lawyers “to just give as many reasons as possible and hope that one will be acceptable.”

Justice Breyer added that the sheer number of explanations offered for striking black potential jurors was suspicious. It reminded him, he said, of excuses his grandson might offer for not doing homework.

In the jury case, he said, “I think any reasonable person looking at this would say, no, his reason was a purpose to discriminate on the basis of race.”

Mr. Foster was convicted by an all-white jury and sentenced to death. He has spent decades on death row and is seeking a new trial.