William Heirens, the notorious “Lipstick Killer” who in 1946 confessed to three horrific murders in Chicago and then spent the rest of his life — more than 65 years — in prison despite questions about his guilt, was found dead Monday in the Dixon Correctional Center in Dixon, Ill. He was 83.

He was pronounced dead at the University of Illinois at Chicago Medical Center, where an autopsy was performed, the Cook County Medical Examiner’s Office said. No cause of death was given, although he was known to have had diabetes.

Heirens’ notoriety stemmed from the separate killings of two women, Josephine Ross and Frances Brown, in 1945. At the scene of the second murder, that of Brown, who had been shot and stabbed, someone had used lipstick to scrawl on a wall: “For heaven’s sake catch me before I kill more. I cannot control myself.”

The reports of a “lipstick killer” terrified Chicago as the press took note of other unsolved murders of women. Then, about two weeks after the Brown murder, on Jan. 7, 1946, a 6-year-old girl named Suzanne Degnan was discovered missing from her bedroom at her North Side home. A ladder was found outside the window. The police later determined that the killer had strangled her and taken the body to the basement of a nearby building, where it was dismembered. Her head, a ribbon still in her hair, was found in a sewer; other body parts were found scattered about the neighborhood.

The newspapers called the killing the crime of the century, and though the police questioned a parade of suspects, there was no arrest.

Almost six months later, Heirens, then 17, was apprehended at the scene of a burglary in the neighborhood. The police charged him with the girl’s murder after determining that his fingerprints were on a $20,000 ransom note that had been left behind at her home.

While he was in custody, The Chicago Tribune, citing what it called “unimpeachable sources,” reported that Heirens had confessed to the Degnan murder. Four other Chicago newspapers followed suit with articles based on The Tribune’s.

Heirens, who said he was beaten and given “truth serum” in jail, disputed the accounts, saying he was about to sign a confession in exchange for one life term but rebelled at “being forced to lie to save myself.” Prosecutors then charged him with the two earlier murders, saying they had incriminating physical evidence, including crime-scene fingerprints and handwriting analysis. Offered a plea bargain in which he would agree to three consecutive life terms, he accepted. Later he said he had done so only to avoid a death sentence if he had gone to trial.

“I confessed to live,” he said.

When he did confess, his memory seemed ragged. Time after time during the plea bargaining, prosecutors brought up details from The Tribune article, which he then incorporated into his testimony.

Heirens recanted his confession soon afterward and maintained his innocence for the rest of his life while being denied parole or clemency numerous times. He questioned the validity of the fingerprints and other physical evidence, as have public interest lawyers who supported him.

In one clemency petition in 2002, his lawyers from the Northwestern University Center on Wrongful Convictions alleged more “prosecutorial misconduct, incompetent defense counsel, unprecedented prejudicial pretrial publicity, junk science, probably false confessions and mistaken eyewitness identification — than any other case we have studied.”

But others could not ignore his explicit admissions of guilt, even if he retracted them. “He is the yardstick by which all evil is judged,” Thomas Epach, a Chicago police official, said at his 2002 clemency hearing.

Suzanne Degnan’s family has fought all efforts to release him.

William George Heirens was born on Nov. 15, 1928, in Evanston, Ill. His father’s flower business failed, and the family teetered on the edge of poverty. In interviews, Heirens said he had burglarized houses to relieve the tension he felt at home from his parents’ frequent fights. He did not try to sell the things he stole, he said.

He was placed in two Roman Catholic youth detention centers. At the second, he proved to be an excellent student. He skipped his senior year of high school and was admitted to the University of Chicago at 16. He had planned to major in engineering.

In interviews, Heirens said his mother had led him to believe that sex was dirty. When he kissed a girl, he said, he would burst into tears and vomit. He said one reason he broke into houses was to play with women’s underwear.

In the burglary in which he was arrested, the police testified that he had aimed a gun at an officer and twice pulled the trigger, but that the weapon misfired. He was additionally convicted of assault with the intention of killing a police officer.

After Heirens went to jail, his parents and brother changed their names to Hill. He left no known survivors.

Heirens became the first prisoner in Illinois to earn a degree from a four-year college. He also managed the prison garden factory and set up several education programs. In recent years, his diabetes damaged his eyesight, and he used a wheelchair. He told The New York Times in 2002 that he had learned that prison friendships were fleeting.

“Most of them, you hear for a little while, and then they kind of fade out,” he said. “Usually when they get out, they try to forget they were ever in.”