A man described as a key suspect has become the fourth person arrested in the case accusing O.J. Simpson of 10 felonies in the armed robbery of sports memorabilia collectors in a casino hotel room.

The man was arrested Tuesday after turning himself in to Las Vegas police, authorities said. Police have described Michael McClinton, 49, of Las Vegas, as "a key player."

McClinton arranged through his attorney to surrender. Two other men who have not been identified also are being sought by police.

Simpson was arrested Sunday after a collector reported that a group of armed men charged into his hotel room and took several items the former NFL great claimed belonged to him.

Click here to read the criminal complaint filed against O.J. Simpson.

Click here to see photos of O.J. Simpson's arrest.

Simpson was booked on suspicion of assault and robbery with a deadly weapon. Clark County District Attorney David Roger filed those charges and added kidnapping and conspiracy to commit kidnapping, according to court documents.

Simpson, who was accused along with three other men, was also charged with one misdemeanor. He faces the possibility of life in prison if convicted.

According to the charges filed Tuesday, Simpson and the others went to the room under the pretext of brokering a deal with the men. Once in the room, Simpson prevented one of the collectors from calling emergency authorities on his cell phone "by ripping it out of Bruce Fromong's hand" while one or more accomplices pointed or displayed a handgun.

The complaint does not specify which of the men involved was carrying the weapon.

Simpson's lawyer, Yale Galanter, said he planned to ask for Simpson's release on his own recognizance.

"If it was anyone other than O.J. Simpson, he would have been released by now," Galanter said.

Simpson has insisted he was not armed and that he went to the hotel simply to retrieve property that had been stolen from him.

"You can't rob something that is yours," Galanter said. "O.J. said, 'You've got stolen property. Either you return it or I call the police."'

Witnesses and authorities have said that they don't believe Simpson had a gun but that some of the men who accompanied him during the confrontation were armed.

Two others named in the complaint, Walter Alexander and Clarence Stewart, have been arrested and released. Authorities were seeking an arrest warrant for a fourth man, Michael McClinton, 49, of Las Vegas, a man police describe as "a key player" in the alleged theft.

"We hope to have him in custody today," said officer Ramon Denby, a police spokesman. "Hopefully, he'll be cooperative and surrender with his attorney."

Alexander, one of the men arrested with Simpson, said Tuesday that Simpson may have been tricked because another memorabilia dealer who tipped him off also recorded everything on tape.

"It sounds like a setup to me," Alexander told ABC's "Good Morning America." He said Simpson had thought the memorabilia belonged to him after getting a call from the dealer.

Simpson and the other three men are charged with: two counts of first-degree kidnapping; two counts of robbery with use of a deadly weapon; burglary while in possession of a deadly weapon; two counts of assault with a deadly weapon; conspiracy to commit kidnapping; conspiracy to commit robbery; and a misdemeanor, conspiracy to commit a crime.

Simpson also faces one charge of coercion with use of a deadly weapon, a felony.

Bruce Fromong, one of the collectors in the room at the time, spoke publicly about the incident on Monday and described Simpson and a group of men coming into the hotel room "commando style."

Later Monday, Fromong had a heart attack. He was in critical condition Tuesday, according to a spokeswoman at Cedars-Sinai Medical Center in Los Angeles.

Earlier Tuesday in California, a judge gave Fred Goldman a week to come up with a list of sports memorabilia O.J. Simpson is accused of stealing from the Vegas hotel room, but he refused to order Simpson to hand over his earnings from everything from autograph signings to video games.

Simpson was acquitted more than a decade ago of the 1994 murders of his ex-wife Nicole Brown Simpson and Goldman's son, Ron. He was later found liable for the slayings in a wrongful death trial.

The civil jury returned a $33.5 million judgment against Simpson, but it remains largely unpaid. The Goldman family has waged a campaign to claim Simpson's assets since then.

In court in Santa Monica, David Cook, an attorney for Fred Goldman, accused Simpson of "sitting on a treasure trove of sports memorability" while ignoring the multimillion-dollar judgment. But both Cook and Simpson lawyer Ronald Slates said they had no idea what the items were, and Slates argued it was unclear whether Simpson really owned any of them.

Cook also filed a new request to get Simpson's watch, which he described as a Rolex Submariner that he saw the former football star wearing in a photo featured on the celebrity Web site TMZ.com. Such watches sell for $5,000 or more, he said.

He also argued that Simpson was wealthy, citing a 2003 tax form indicating income of $400,000.

Slates noted Simpson has expenses for his three children. "He has a right, like everybody else, to be protected (under the law)," Slates said.

Slates also said Simpson has repeatedly offered to settle the judgment with the Goldman family.

"It is inconceivable that the father of a murder victim would sit and haggle," Cook said.