He has tumbled in the public eye from revered football hero and actor, to reviled wife abuser and murder defendant, to indebted and hapless convicted robber, but O.J. Simpson went before a Nevada parole board on Thursday flashing his usual self-assurance, telling the board that he was “a good guy” and asserting, implausibly, “I basically have spent a conflict-free life.”

Whether or not the four board members believed him, they voted unanimously to grant him parole when he first becomes eligible on Oct. 1, after nine years in state prison on charges stemming from a 2007 armed robbery in a Las Vegas hotel room. Appearing on a video link from Lovelock Correctional Center, Mr. Simpson spoke to the board in Carson City as, officially, just another inmate who looked like a good bet for release, a 70-year-old who has been a model prisoner.

But of course, it is the 1994 knife murders of his ex-wife Nicole Brown Simpson and her friend Ronald Goldman, for which he was acquitted after one of the most-watched trials in history, that have cast the longer, darker shadow over his life and reputation. No celebrity so big had been tried for a crime so severe, and a generation later, he stands as someone who unwittingly helped shape the modern news media and popular ideas about the law, police, race relations and Los Angeles, the city he once called home.

“Obviously, there was a 10,000-pound elephant in that room,” Mr. Simpson’s lawyer, Malcolm Lavergne, said after the parole hearing. “Mr. Simpson is obviously a very polarizing figure.”