LAS VEGAS — Nearly a year after O.J. Simpson walked into a casino hotel room intent on reclaiming some sports memorabilia, he and his lawyers walked into a courthouse today to pick jurors for his robbery-kidnapping trial.

The fallen NFL star, actor, and advertising pitchman, and his remaining co-defendant, Clarence “C.J” Stewart, a 54-year-old golfing buddy from North Las Vegas, have both pleaded not guilty to 12 charges stemming from a heated encounter last September with two sports collectibles dealers peddling Mr. Simpson memorabilia at a Las Vegas hotel-casino.

Mr. Simpson’s arrival at the Clark County Regional Justice Center this morning was much more subdued than previous appearances at the courthouse, with no protesters and few people to greet him.

He declined to answer questions, but smiled and waved when one person called out “Good Luck!”

Mr. Simpson has said he put his faith in the jury system and was confident of an acquittal — a conviction could put him away for life.

During the weekend, Mr. Simpson was stopped by Nevada Highway Patrol troopers on Interstate 15 south of Las Vegas after someone he spoke with at a gas station reported he appeared to be intoxicated, an NHP trooper, Kevin Honea, said.

“No signs of alcohol were detected, and he was on his way,” Mr. Honea said today. “It looks like the only thing he did was be nice to somebody at a gas station.”

A lawyer, Robert Lucherini, lost several last-ditch bids to get the Nevada Supreme Court to postpone or sever Mr. Stewart’s trial from Mr. Simpson’s.

He argued Mr. Stewart can’t get a fair trial before a jury sure to know about Mr. Simpson’s acquittal in Los Angeles in the 1994 slayings of his ex-wife Nicole Brown Simpson and her friend Ronald Goldman. After the “Trial of the Century,” Mr. Simpson was found civilly liable for the deaths and ordered to pay a $33.5 million judgment to Goldman’s family.

Prosecutors, defense lawyers, and Clark County District Judge Jackie Glass have used 26-page questionnaires to identify prospective jurors with biases and cut a jury pool of 500 to fewer than 250.

Jury selection still could take a week or longer, court officials said.

When the 12-member panel and four alternates are seated, the prosecution will tell them that Mr. Simpson and Mr. Stewart walked into the casino hotel room on Sept. 13, 2007, with four other men and robbed the sports collectibles peddlers at gunpoint of items that Mr. Simpson said had been stolen from him.

Mr. Simpson, 61, who has been living in Miami, maintains he didn’t ask anyone to bring guns and that he didn’t know anyone in the room was armed.

Mr. Simpson and Mr. Stewart have pleaded not guilty to the charges, which include burglary, coercion, and assault with a deadly weapon. A robbery conviction would mean mandatory prison time. A kidnapping conviction carries the possibility of life in prison with the possibility of parole.

Four of the men who accompanied Mr. Simpson — Charles Cashmore, Walter “Goldie” Alexander, Michael “Spencer” McClinton and Charles Ehrlich — pleaded to lesser felony charges and agreed to testify for the prosecution.

But a Simpson defense attorney ,Yale Galanter, got Alexander to admit that he would have slanted his testimony in Mr. Simpson’s favor if the price was right.

“Alexander offered to sell his testimony to the highest bidder,” Mr. Galanter said as he prepared for trial. He promised to expose troubled backgrounds of the witnesses lined up against Mr. Simpson.

“This is a cast of very nefarious characters,” Mr. Galanter said. “And the truth is, these items were not memorabilia. The law has always provided a right, dating back to our founding fathers, to recover personal property.”