The cause was a heart attack, his daughter Regina Whitmore said.

Mr. Whitmore was 19 in April 1964 when he was first picked up on a Brooklyn street, in Brownsville, for questioning about an attempted rape in the neighborhood the night before. A soft-spoken young man, he had grown up in a house in a junkyard that his father owned in Wildwood, N.J. He had tried hard in school but dropped out at 17, moved to Brooklyn and was waiting for a ride to work when the police pulled their car over and started asking him questions.

He would later tell interviewers that he had secretly been pleased at being asked for help in solving a crime, and at the prospect of having a good yarn to tell his friends.

But when his interrogation ended several days later, Mr. Whitmore had confessed to the attempted rape, and to the rape-murder a few weeks earlier of another woman in the neighborhood, Minnie Edmonds. He had also confessed to the double murder in Manhattan, on Aug. 28, 1963, of two women whose bodies were found bound and stabbed numerous times in the apartment they shared on East 88th Street.

Called "the Career Girl Murders" in newspaper headlines, the killings of Janice Wylie, 21, a researcher at Newsweek magazine, and Emily Hoffert, 23, a schoolteacher, had been the focus of an eight-month investigation.

Mr. Whitmore recanted his confession, and he consistently claimed afterward that the police had beaten him and that he had signed the confession without knowing what it was. He said he was innocent. And in the case of the Wylie-Hoffert slayings, he said, he could provide the names of a dozen people who saw him on that day and who would remember it, because it was the day of the civil rights march on Washington, when Martin Luther King Jr. gave his "I Have a Dream" speech. He and everybody else in Wildwood had watched it on television and talked about it incessantly, all day, he said.

In 1964, Mr. Whitmore was convicted by a Brooklyn jury on the charges of attempted rape. Though the verdict was overturned because jurors were found to have been reading newspaper accounts of the case, which referred to Mr. Whitmore as the "prime suspect" in the Career Girl Murders, he was tried a second time. He was convicted again, but the verdict was again thrown out, on different grounds.

By 1965, Manhattan prosecutors had evidence that Mr. Whitmore was wrongly accused in the Wylie-Hoffert murders. They had linked the brutal slayings to Richard Robles, a recently released prisoner who would later be convicted of the crime, and who remains in prison.

Still, while Mr. Whitmore now faced a second trial, in the murder of Ms. Edmonds, his indictment in the Wylie-Hoffert case remained in place. News accounts said that by refusing to dismiss the indictment, prosecutors hoped to deny Mr. Whitmore's defense lawyers an argument: that the dismissal of the double-murder indictment proved it had been coerced, and that Mr. Whitmore's confession to the Edmonds murder, elicited in the same long interrogation, had therefore been coerced, too.

Selwyn Raab, a reporter then for The New York World-Telegram and Sun, and later for The New York Times, had found a dozen witnesses who remembered seeing Mr. Whitmore in Wildwood on the day of the double murder. They had bumped into him in the homes of friends and relatives while watching Dr. King's speech, Mr. Raab wrote in a front-page story in The World-Telegram.

"Whitmore's case showed how fragile the whole system was, and still is," Mr. Raab said in an interview on Sunday. "Even now, police use the same techniques to manipulate suspects into giving false confessions. And 90 percent of convictions are still based on confessions."

The police and prosecutors at the time denied any misconduct. Legal reformers asked Gov. Nelson A. Rockefeller, a Republican, to appoint a panel to investigate, but he declined.

Yet Mr. Whitmore's legal troubles were far from over. With the Manhattan district attorney still refusing to clear him entirely in the Wylie-Hoffert case, Mr. Whitmore went to trial for the murder of Minnie Edmonds, solely on the evidence of his "confession."

In the debate in the New York State Legislature over a proposal to abolish the death penalty, Mr. Whitmore's case became a warning cry against the killing of innocents. "In Whitmore's case," said Assemblyman Bertram L. Podell of Brooklyn, "we have learned to our shock and horror that a 61-page statement of completely detailed confession was manufactured and force-fed to this accused."

Governor Rockefeller signed a bill in 1965 abolishing capital punishment, except in the killing of police officers. (The death penalty was reinstated in 1995, and declared unconstitutional in 2004.) The Supreme Court cited Mr. Whitmore's case as "the most conspicuous example" of police coercion in the country when it issued its 1966 ruling establishing a set of protections for suspects, like the right to remain silent, in "Miranda v. Arizona."

Mr. Whitmore was tried several times in the murder of Ms. Edmonds, with each trial ending in a hung jury.

As a result of the various cases in which he had become entangled, he was in and out of prison, for months and years at a time, until April 10, 1973, when the Brooklyn district attorney, Eugene Gold, dismissed the last case against him — a retrial of the attempted rape case — with new evidence exonerating Mr. Whitmore. On his release from custody that day, Mr. Whitmore said that what he felt was "just beyond expressing," adding "I'm not bitter. I appreciate greatly what the D.A. did."

His life after prison was marked by depression and alcoholism, said T. J. English, author of "The Savage City: Race, Murder and a Generation on the Edge," in which Mr. Whitmore's life is chronicled.

Mr. Whitmore moved back to Wildwood, operated a commercial fishing boat for a time, and was later disabled in a boating accident. He was unemployed for long stretches.

Mr. Whitmore's daughter Regina said he had children but never married.

Besides her, she said, his survivors include three other daughters, Aida, Sonya and Tonya, and two sons, George and James, all of whom have taken the name Whitmore, and more than 20 grandchildren.

"He told us about what happened to him," she said. "But he said he never held it against anybody. He was always a very sweet man with us. He wanted us to grow up happy."

 

This article has been revised to reflect the following correction:

Correction: October 15, 2012

An earlier version of the headline with this article incorrectly stated the number of murders to which Mr. Whitmore confessed. It was three, not two.