Las Vegas, Nevada (CNN) -- Disgraced football legend O.J. Simpson was in a Las Vegas courtroom Monday in a bid to get his robbery, assault and kidnapping convictions thrown out.
Dressed in a blue prison uniform, the Heisman Trophy winner and former Buffalo Bills star halfback appeared to have grayed some during his four years of incarceration. He listened intently through hours of testimony, which concluded Monday evening.
Simpson, who is serving a 33-year prison term, is asking for a new trial. In court papers, he's arguing that bad legal advice led to his arrest and conviction in a 2007 confrontation with sports memorabilia dealers.
Simpson accuses his old lawyer, Yale Galanter, of having a conflict of interest and of failing to mount an effective defense in his trial. He also says Galanter told him before that confrontation that he was within his rights to take back property he believed had been stolen from him, "so long as there would be no trespass and no physical force used against the persons with the property."
Among the witness called on Monday was Arnelle Simpson, one of O.J. Simpson's daughters, who said she and her father had dinner with Galanter and his wife the night before the incident took place.
Simpson, 65, was convicted of leading a group of associates into a room at the Palace Station hotel and casino and using threats, guns and force to take back the items from the two dealers.
"Simpson also contends that Galanter did not advise Simpson that carrying out the plan could subject him to criminal charges, regardless of the ownership of the property," his new lawyers wrote in seeking a new trial.
Simpson also blames Galanter for preventing him from testifying in his own defense. Without putting him on the stand, "There was no evidence presented to adequately challenge the state's evidence of criminal intent and knowledge of the guns or the bad character evidence to which the jury was exposed," his appeal states.
The Nevada Supreme Court already upheld his conviction in 2010. Prosecutors have called the new attempt to reverse his conviction "without merit," and Galanter is quoted in court papers as telling the judge in the original trial that he spoke to Simpson only after the confrontation.
"Other than Simpson's bare allegations, the record does not support any conflict of interest," prosecutors wrote in response to Simpson's claims.
Galanter could not be immediately reached for comment Sunday.
Simpson's October 2008 conviction came on the anniversary of his famous acquittal on murder charges in the 1994 deaths of his ex-wife, Nicole Brown Simpson, and her friend Ronald Goldman. Though cleared of criminal charges, a civil jury later slapped him with a $33 million wrongful-death judgment, and lawyers for the Goldman family have doggedly pursued his assets.
His current sentence leaves him eligible for parole in 2017.