Robert Blake, an actor whose career portraying gritty characters like the television detective Tony Baretta was eclipsed by his trial and acquittal in the murder of his wife in 2001, died Thursday at his home in Los Angeles. He was 89.

The cause was long-term heart disease, Noreen Austin, his niece, said.

Mr. Blake began performing at 2, when his father would bring him and his brother and sister to New Jersey parks to dance for money. By age 5 he was a regular in the “Our Gang” film comedies.

He went on to act in scores of films and on hundreds of television shows, all the while making regular visits to late-night talk shows, where he delighted in spouting flagrantly unorthodox views and savagely mocking his own career.

He also earned a reputation as a Hollywood enfant terrible. He insulted producers, punched a director, fought with fellow actors, abused alcohol and drugs, and sometimes went for years without work.

He nonetheless became a television star in the late 1970s as Baretta, a detective who lived in a run-down hotel, had a pet cockatoo named Fred and used disguises — waiter, wino, janitor, barber — to chase bad guys. His catchphrase, “You can take dat to da bank,” became well known.

One of Mr. Blake’s most acclaimed roles was certainly scary: the mass murderer Perry Smith in “In Cold Blood,” the 1967 film adaptation of Truman Capote’s true-crime book. In an interview with Playboy in 1977, Mr. Blake explained that he had sought the part to explore a question that nagged him.

“Everybody knows what a murderer is a millionth of a second after he pulls the trigger,” he said. “But what is he a millionth of a second before he pulls the trigger?”

A jury — and a transfixed American public — pondered whether he could answer that question during his trial, from late 2004 to March 2005, in the shooting death of his wife, Bonny Lee Bakley.

The details of the case could have come from a pulp novel. Witnesses portrayed Mr. Blake as trolling jazz clubs for women, then wooing them in the back seat of his truck. Ms. Bakley was alleged to be a petty criminal who sold nude pictures of herself to lonely men through the mail. She had nine former husbands and a dozen aliases and was on probation for fraud, according to court testimony.

By 1999 she was in Los Angeles. She met Mr. Blake at a nightclub and, as both acknowledged, had sex with him in his car that night. At the time, she was having a sexual relationship with Christian Brando, the eldest son of Marlon Brando. When she gave birth to a daughter, tests revealed that the father was Mr. Blake and not Mr. Brando, whom she had first identified.

Mr. Blake, whose marriage to the actress Sondra Kerr ended in divorce in 1983 after 22 years, said he had agreed to marry Ms. Bakley for the good of their daughter, Rose. According to trial testimony, the marriage was strained, and Ms. Bakley lived in a separate house on his property. Witnesses said he referred to his wife as a “pig” and spoke of wanting to “snuff” her.

On May 4, 2001, Ms. Bakley, 44, was found dead from a gunshot to her head in her husband’s Dodge Stealth, parked outside an Italian restaurant in the Studio City section of Los Angeles, where the couple had just dined. Mr. Blake said he was not there when she was shot; he said he had gone back to the restaurant to retrieve a gun he had left in a booth.

That gun, it was determined, was not the murder weapon; one found in a nearby dumpster was.

By April 2002, the police had nonetheless gathered enough evidence to charge Mr. Blake with “murder with special circumstances,” a capital offense. He was also charged with soliciting movie stuntmen to do the killing for him.

After he pleaded not guilty to all charges, the Los Angeles District Attorney’s Office announced it would not seek the death penalty. Mr. Blake was initially denied bail and spent 11 months in jail, until March 2003, when he was granted bail, set at $1.5 million, and posted it, allowing him to remain free for almost two years while he awaited trial.

On March 16, 2005, after a three-month trial in which the stuntmen testified to having been solicited by Mr. Blake to kill Ms. Bakley, the jury decided that the prosecutors had not proved Mr. Blake’s guilt. In interviews afterward, jurors said the stuntmen had not been credible because they had admitted to being drug addicts. Mr. Blake said three restaurant workers had seen him return to get his gun, but he did not produce them.

Ms. Bakley’s family later sued Mr. Blake in civil court for wrongfully causing her death. They won a $30 million judgment, which, after Mr. Blake appealed, was cut in half on the grounds that Ms. Bakley had been earning her living by illegal means. Mr. Blake filed for bankruptcy in 2006.

April Rubin contributed reporting.