New York Times

WASHINGTON — The Supreme Court issued rulings on Monday in favor of a death row inmate whose lawyer disobeyed his instructions and a driver of a rental car that was searched without his permission after the police learned he was not listed as an authorized driver on the rental agreement.

The death penalty case concerned Robert McCoy, who was sentenced to death in Louisiana after his lawyer told the jury Mr. McCoy had committed a triple murder.

Mr. McCoy had insisted that he was innocent and had told his lawyer, Larry English, that he wanted to clear his name. But Mr. English pursued a different strategy in the 2011 trial, hoping that a candid acknowledgment of his client’s actions would earn him credibility during the trial’s sentencing phase.

Justice Ruth Bader Ginsburg, writing for the majority in the 6-to-3 decision, said Mr. English was not entitled to disregard his client’s instructions. His disloyalty, she wrote, required a new trial.

“We hold that a defendant has the right to insist that counsel refrain from admitting guilt, even when counsel’s experienced-based view is that confessing guilt offers the defendant the best chance to avoid the death penalty,” Justice Ginsburg wrote. Chief Justice John G. Roberts Jr. and Justices Anthony M. Kennedy, Stephen G. Breyer, Sonia Sotomayor and Elena Kagan joined her opinion.

In dissent, Justice Samuel A. Alito Jr. wrote that Mr. English had not conceded his client’s guilt but only that he had killed his victims. Mr. English continued to maintain that his client was not guilty, Justice Alito wrote, by arguing that he lacked the intent required to make him guilty of first-degree murder. Justices Clarence Thomas and Neil M. Gorsuch joined Justice Alito’s dissent.

Mr. McCoy was convicted of the 2008 killings of Christine Colston Young, Willie Young and Gregory Colston, who were the mother, stepfather and son of Mr. McCoy’s estranged wife. There was substantial evidence that he had committed the crimes and some reason to think that Mr. McCoy’s belief in his innocence was delusional.

But there was no dispute about Mr. McCoy’s instruction to Mr. English. He was adamant that he was innocent and that others had carried out the murders. Mr. English disagreed.

During his opening statement at the trial, Mr. English used the strategy he had promised. “I’m telling you,” he told the jury, “Mr. McCoy committed these crimes.”

The decision relied on a unanimous 2004 ruling from the United States Supreme Court in Florida v. Nixon, which said lawyers need not obtain their clients’ express consent before conceding guilt in a capital case. But the ruling did not address whether it was permissible for a lawyer to disregard a client’s explicit instruction to the contrary.

Justice Ginsburg wrote that the new case, McCoy v. Louisiana, No. 16-8255, raised that question.

"Larry English was placed in a difficult position; he had an unruly client and faced a strong government case,” she wrote. “He reasonably thought the objective of his representation should be avoidance of the death penalty. But McCoy insistently maintained: ‘I did not murder my family.’ Once he communicated that to court and counsel, strenuously objecting to English’s proposed strategy, a concession of guilt should have been off the table.”

In the car rental case, the court unanimously ruled that drivers do not lose their constitutional right to privacy solely because they are not listed on the rental agreement.

“The mere fact that a driver in lawful possession or control of a rental car is not listed on the rental agreement will not defeat his or her otherwise reasonable expectation of privacy,” Justice Kennedy wrote for the court.

The case started in 2014, when Terrence Byrd was pulled over by a state trooper on an interstate highway in Pennsylvania. His fiancée had rented the car, from Budget, and he was using it with her permission. But he was not listed on the rental agreement as an authorized driver.

On learning that Mr. Byrd was not an authorized driver, the trooper maintained that he was free to search the car without Mr. Byrd’s consent. He found 49 bricks of heroin in the trunk.

After a judge refused to suppress the evidence, Mr. Byrd was convicted on federal drug charges and sentenced to 10 years in prison.

Justice Kennedy said the words of the rental agreement did not give the authorities the right to search the car without Mr. Byrd’s consent. But he sent the case back to the lower courts to examine two questions left open in the case, Byrd v. United States, No. 16-1371.

The first was whether Mr. Byrd had “intentionally used a third party as a straw man in a calculated plan to mislead the rental company from the very outset, all to aid him in committing a crime.” The second was whether the trooper had probable cause to search the car.

A version of this article appears in print on May 14, 2018, on Page A14 of the New York edition with the headline: Supreme Court Rules For Death Row Inmate Betrayed by His Lawyer