LAS VEGAS -- Once upon a time, O.J. Simpson was a national sports hero, showered with adulation and endorsement contracts. He was the "Juice" -- a Hall of Fame football star, actor, TV commentator and pitchman with a beautiful wife, two picture-book cute children and a Rolls-Royce.

But the stabbing death of his ex-wife more than 14 years ago makes those early days seem like a fairy tale for Simpson. It was a life before allegations of murder, robbery and kidnapping, before the world he knew ended and a darker one began.

The next chapter unfolds Monday in a Las Vegas courtroom and could determine how and where the rest of his life plays out. A jury will be picked to decide whether Simpson and co-defendant Clarence "C.J." Stewart should go to prison on 12 charges, including armed robbery and kidnapping.

Simpson, 61, is accused of leading a curious collection of characters to a casino hotel room, where they were accused of holding two sports collectibles dealers at gunpoint and taking memorabilia that Simpson maintains belonged to him.

The tale of the hotel room heist is filled with men of questionable and sometimes criminal backgrounds, allegations of guns, threats and denials.

Simpson, who lives in Miami, has said he was trying to retrieve personal belongings and family heirlooms, that he didn't ask anyone to bring guns and that he didn't know anyone in the room was armed.

But four of the five men who accompanied him have pleaded guilty and agreed to testify against Simpson.

One, Michael McClinton, testified that Simpson asked him to bring guns and told him to look "menacing" during the confrontation with sports memorabilia dealers Bruce Fromong and Alfred Beardsley.

McClinton testified that he displayed a handgun and gave another to former co-defendant Walter Alexander.

McClinton, Alexander and former co-defendants Charles Ehrlich and Charles Cashmore have pleaded guilty to lesser felony charges and will be sentenced after they testify at the trial, which is scheduled to take five weeks.

Hanging over the proceedings will be the shadow of the 1994 slaying of Simpson's ex-wife, Nicole Brown Simpson, who was found slashed to death along with friend Ronald Goldman.

As a stunned nation looked on, Simpson led a slow-speed chase in a white Ford Bronco, was charged with the murders and hired a legal "dream team."

A year later, after a televised trial watched by millions, he was acquitted. A civil jury later held him liable for the killings, but he hasn't paid the $33.5 million in damages, insisting he did not commit the slayings.

And then Simpson retreated to Florida seemingly intent on living the life of a retiree, playing golf every day and looking after his children.

But things have not been idyllic for Simpson.

He was tried in a road rage case and acquitted. Family disputes went public.

And now, in a strange postscript, O.J. Simpson's latest trial could end with him going to prison for a long time, maybe even the rest of his life.

A kidnapping conviction carries the possibility of life in prison and a robbery conviction would mean mandatory prison time.

This latest episode resulted from a clash between past and present -- Simpson's obsession with keeping control of memorabilia from his glory days.

One of the men expected to testify against him, Thomas Riccio, a convicted felon and the memorabilia dealer who arranged the meeting, said Simpson's motive was clear when he went to the hotel room at the Palace Station casino a year ago and demanded the return of items he said belonged to him.

"O.J. wanted to be able to pass these things down to his kids," Riccio said.

The memorabilia dealer, who has known Simpson for many years and got a book published as a result of the Las Vegas case, acknowledged letting Simpson into the hotel room with a key.

He also had a tape recorder running inside the room and later sold an audio tape of the events to a gossip Web site. The audio tape will be key evidence against Simpson, along with the testimony of the four former co-defendants, Riccio, Beardsley and Fromong.

Clark County District Attorney David Roger and prosecutor Chris Owens say Beardsley and Fromong were lured to the room and held against their will at gunpoint.

Defense lawyer Yale Galanter say prosecutors overreached for charges against Simpson. He called the witnesses against him "a cast of very nefarious characters" with credibility problems and a financial incentive to twist their stories.

Riccio was not the only one to cash in after the incident. Mike Gilbert, another memorabilia dealer who was mentioned during the robbery recording and accused by some of stealing items from Simpson, published his own tell-all book claiming Simpson had once confessed to murdering his ex-wife.

It's unclear whether Gilbert will be called to testify.

Simpson tarnished whatever gloss was left on his image in 2006 by cooperating in a book called "If I Did It," a hypothetical story he claimed was a fictional account of how he might have killed his ex-wife and Goldman.

Simpson was paid $880,000 up front and said he knew it was "blood money."

The book was so controversial that it was withdrawn from stores and led to the firing of the publisher. Goldman's father, who had fought the publication, ultimately published it himself, claiming it was Simpson's confession.

The publication came on the same day that Simpson was arrested in Las Vegas.

Some believe the new trial will be shadowed by memories of things past.

"For the public, it's justice delayed," said Jerry Reisman, a Garden City, N.Y., attorney who represented Simpson on business matters before the murder case.

"The public is tired of O.J. I think the public is going to see and hear what they want to and hope that he is convicted," Reisman sad. "It's going to be difficult for O.J. to get a fair trial. A lot of the public believes he was guilty of the crimes he was charged with back then and he got away with it."

The challenge for Simpson's attorneys will be to keep the focus on the current charges, he said.

Ian Weinstein, a professor of criminal law at Fordham University who has followed Simpson's legal travails over the years, said the "celebrity factor" may weigh in favor of Simpson if jurors are old enough to remember his triumphs as well as his downfall.

"Some of us have a longer view of him," Weinstein said. "My students in our law school know him only as a celebrity with legal problems. But to me, he's still the guy running through the airport in the Hertz commercials."

Weinstein said studies of juror attitudes show that celebrities fare better in court because "Jurors will have a sense that they know him and it will translate to a sense of familiarity and liking him. … Because they feel they know him, they would feel an obligation to think carefully about the facts of the case."

Then again, he said, there may be jurors who don't like him and, "They feel they're going to get him this time."