Las Vegas  - Former American football legend O. J. Simpson went on trial Monday on charges of armed robbery but suffered an immediate setback when the judge rejected a request from his attorneys to ask potential jurors if they considered Simpson a murderer.

Simpson, 61, was sensationally acquitted in the 1994 slayings of his ex-wife, Nicole Brown Simpson, and her friend Ronald Goldman, though a civil jury later found him liable for the deaths.

Now he is on trial for allegedly robbing two dealers in sports collectibles at gunpoint at a seedy Las Vegas hotel last September. Together with codefendant Clarence "C. J." Stewart, 54, Simpson faces a dozen charges, including kidnapping, which carries a potential life sentence.

Simpson's lawyers had hoped to disqualify jurors with a negative opinion of the notorious sports figure but Clark County District Judge Jackie Glass turned down the bid by his attorneys, saying questionnaires filled out by the jury pool already asked about Simpson's other trials.

The jury selection process is expected to take a week or more and the trial is expected to last about five weeks.

Simpson claims that he was merely trying to recover memorabilia taken without his permission from his trophy room and that he was unaware that some of the men who were with him were carrying guns. However prosecutors hope to contradict that argument with evidence from Simpson's accomplices, some of whom have been granted immunity in return for their testimony. (dpa)