A judge denied his bid for a new trial on claims of ineffective legal counsel, ruling the evidence is overwhelming that Simpson "planned, organized and led" a group of armed men in a confrontation with two sports memorabilia dealers six years ago.
Simpson's lawyers vowed Wednesday to keep appealing for his freedom.
"He was disappointed and disheartened, as was his family," lawyer Patricia Palm said of Simpson's reaction to the news. "But we're definitely not giving up."
Simpson is serving nine to 33 years for his conviction on armed robbery, kidnapping and other charges. He was granted parole on some convictions in July, but still faces at least four more years in prison.
Simpson's next opportunity for freedom will be in an appeal to the Nevada Supreme Court. His legal team planned to file a notice of appeal as early as next week with the state's highest court. Palm said they're also preparing a federal court claim that Simpson's fair trial rights were violated.
"He is looking forward to the appeal," Palm said. "We're confident that when we get to the right court we'll get relief because he deserves relief."
The 101-page ruling by Clark County District Court Judge Linda Marie Bell came more than six months after she held five days of hearings on claims that Simpson's former lawyer botched his 2008 trial and appeals to the Nevada Supreme Court. The hearings included testimony by Simpson, who was acquitted in 1995 in the stabbing deaths of his ex-wife and her friend.
In her order released after business hours Tuesday, the judge ruled Simpson "failed to pinpoint significant errors that either alone or combined would have changed the outcome of his case. Additionally, Mr. Simpson has failed to demonstrate significant errors from his appeal."
The lawyer who handled Simpson's trial and appeals, Yale Galanter, faulted Simpson's current attorneys for questioning his work and said he felt vindicated.
"In an effort to capture the spotlight, O.J.'s new legal team created a laundry list of falsehoods and attacked my reputation and integrity without contacting me to get the facts, review my files or review any of the documented evidence in the case," Galanter said.
Bell faulted Galanter for collecting excessive fees from Simpson and not hiring experts or investigators for his defence, and identified other mistakes. But the judge said none would have made a difference in the outcome.
Simpson, meanwhile, drew blame for asking men to bring guns during the 2007 caper, then denying he knew anyone was armed, and for failing to follow his lawyer's advice not to use force to obtain items he believed were his.
"Mr. Simpson failed to disclose a material fact, the use of guns, to Mr. Galanter," the judge said. "The evidence does not show Mr. Simpson followed Mr. Galanter's advice."
Bell rejected Simpson's claim that Galanter advised him not to testify in his defence, noting that Simpson declared in open court that he was choosing not to take the stand.
Simpson also contended Galanter never told him about a plea bargain that had been offered by prosecutors that would have had him serve two to five years in prison if he pleaded guilty to robbery. The judge said that because testimony conflicted and no formal offer was documented, she couldn't determine if Galanter ever told Simpson about a plea deal.
Simpson testified in May that he would have taken the deal. If he had, he'd be out of prison now.
In the end, "Nothing indicates that the jury's verdict would have changed had any or all of the issues brought forth by Mr. Simpson been addressed at trial," Bell wrote.
A legal expert who has followed Simpson's legal tribulations since his "trial of the century" acquittal said the ruling indicates the judge strongly believed Simpson was the ringleader of the heist and knew guns would be involved.
"Between his credibility and the lawyer's, she believed the lawyer even though the lawyer did make mistakes," said Laurie Levenson, a Loyola Law School professor.
AP Special Correspondent Linda Deutsch contributed to this report.
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