O.J. Simpson arrived this morning at a Las Vegas courtroom, where he and two codefendants are expected to plead not guilty to 12 charges stemming from the alleged robbery of two men who traffic in sports memorabilia.

Accompanied by his lawyers, Simpson flashed a smile at television cameras as he entered the building to deal with his latest confrontation with the legal system. Wearing a suit in an elegant shade of gray, he seemed at ease, sitting on a railing and smiling as he talked to people in the courtroom.

Simpson, the former football star, actor and pitchman, is perhaps best known for being acquitted in 1995 for the murders of his wife, Nicole Brown Simpson, and her friend Ronald Goldman.

In the current case, Simpson, 60, who now lives in Miami, is charged with kidnapping, armed robbery, assault with a deadly weapon, burglary, coercion and conspiracy charges in connection with a Sept. 13 confrontation with the sports dealers. If convicted, Simpson could face life in prison on the kidnapping charge and mandatory prison time on the robbery charge.

Simpson has maintained that he entered the hotel room to recover personal property that had been stolen by a former agent. The prosecution alleges that Simpson and his colleagues took tens of thousands of dollars of sports collectibles not tied to the star.

The arraignment of Simpson with Clarence Stewart, 53, and Charles Ehrlich, 53, is a pro forma step after a justice of the peace ruled two weeks ago that there was enough evidence for them to be tried.

Clark County District Court Judge Jackie Glass is expected to set a trial date for next year.