George Whitmore Jr., a grade-school dropout who confessed to three New York City murders he did not commit and spent more than three years in prison, died Oct. 8 in a Wildwood, N.J., nursing home. He was 68.

His daughter Regina Whitmore told the New York Times that he died after a heart attack.

Mr. Whitmore was 19 in April 1964 when he was picked up in Brooklyn for questioning about an attempted rape.

By the time his interrogation ended several days later, Mr. Whitmore had confessed to the attempted rape, to the murder a few weeks earlier of another woman in Brooklyn and also to the murders of two young women in Manhattan in August 1963.

Mr. Whitmore later recanted the confessions and maintained his innocence, saying police had beaten him and made him sign a confession without knowing what it was.

Mr. Whitmore was in and out of prison several times until the last case against him was dismissed in April 1973.

His case was cited as an example of police coercion when the U.S. Supreme Court issued its 1966 ruling establishing protections for suspects such as the right to remain silent.

Mr. Whitmore, who grew up in Wildwood, moved back there and operated a commercial fishing boat for a time. He was later disabled in a boating accident.