LAS VEGAS, Nevada (CNN) -- Two men who say they helped O.J. Simpson forcibly take sports memorabilia during a confrontation in a Las Vegas hotel room testified Tuesday that Simpson asked them to carry guns and "look menacing."
Former NFL star O.J. Simpson waits for testimony to begin in a Las Vegas court Tuesday.
Their testimony contradicts Simpson's assertions that he had no idea weapons were involved in the incident.
Walter Alexander and Michael McClinton agreed to testify after reaching plea bargains with prosecutors.
They said Simpson had instructed them to deny guns had been used during the September 13 altercation with two sports memorabilia dealers at the Palace Station hotel.
Their testimony came during the third day of Simpson's preliminary hearing in Clark County Justice Court, which will continue Wednesday morning.
Simpson, 60, has pleaded not guilty to 12 criminal counts in connection with what prosecutors contend was an armed robbery, including conspiracy, kidnapping, robbery, burglary, coercion and assault with a deadly weapon. He could face up to life in prison if convicted.
Earlier Tuesday, McClinton pleaded guilty to reduced charges of conspiracy to commit robbery and robbery, a deal which required his truthful testimony against the remaining defendants. Alexander has also agreed to plead guilty to a charge of conspiracy to commit armed robbery.
The preliminary hearing is being held to determine whether Simpson and two co-defendants -- Charles Stewart and Charles Ehrlich -- should be tried.
Alexander, who described himself as Simpson's former golfing buddy, said Simpson met with him and McClinton outside The Palms casino on the afternoon September 13 and asked them to get "some heat." Simpson asked the men to accompany him to a room at the Palace Station hotel to retrieve items Simpson believed belonged to him, Alexander said.
McClinton testified that Simpson asked to see Alexander's concealed weapons permit and asked them to accompany him as "security" later in the day. He also said Simpson told him there might be a gun in the room where the memorabilia was being sold.
After meeting Simpson, McClinton and Alexander went to McClinton's house to change clothes and retrieve two loaded handguns, McClinton said.
Alexander testified that Simpson initially said he wanted the guns to remain in the men's holsters, but he wanted them to be visible so the people in the hotel room would be intimidated. Watch co-defendant tell of his carrying a weapon »
Alexander said when he asked Simpson what would happen if the police became involved, Simpson said, "F--- the police. Are they going to arrest me for taking my own s---?"
As they prepared to enter the hotel room, Alexander said Simpson told McClinton to take out his gun, a change from his earlier instruction. In his testimony, McClinton quoted Simpson as saying, "Show them your weapon and look menacing."
McClinton said he pulled out his weapon as he entered the room, where Simpson said, "Don't let anybody out of this room." He also said he saw Alexander pull out his weapon briefly before reholstering it, although Alexander testified he did not remember pulling his weapon and wasn't sure if anyone saw it.
Prosecutors allege Simpson and five cohorts held sports memorabilia dealers Bruce Fromong and Alfred Beardsley against their will and removed items Simpson believed has been stolen from him. During his testimony last week, Fromong insisted that the material was his and that he had bought it legally.
Simpson has denied requesting anyone to carry weapons or knowing any guns were used in the confrontation, which the former NFL star and Heisman trophy winner insisted was merely an effort to retrieve his memorabilia.
Another former Simpson co-defendant, Charles Cashmore, has pleaded guilty to robbery and conspiracy to commit robbery. His sentencing has been set for April 15.
Under cross-examination by Simpson attorney Yale Galanter, Alexander admitted leaving a phone message on the voice mail of Tom Scotto, a Simpson friend, asking for help after his arrest. He said he was seeking money to hire an attorney.
When Galanter suggested Alexander had been implying he would tailor his testimony to help Simpson in exchange for money, Alexander said, "I felt like I could lean toward that instead of telling the exact truth."
He said at the time of the call, "I wasn't sure that I wanted the deal" offered to him by prosecutors, which he feared could cost him his real estate license.
Alexander testified that after realizing he had participated in a crime, he asked Simpson if he would bail the men out if they got in trouble. He said Simpson told him, "There won't be any trouble if you get out of town."
He quoted Simpson as saying, "What happens in Vegas stays in Vegas, unless you're O.J. Simpson."
Alexander said Simpson said the men should "just stick" to the story that there weren't any guns used during the incident. He also said when he tried to feel Simpson out about giving them one of the retrieved items as compensation for their efforts, Simpson responded with laughter.
McClinton also testified that Simpson told him that he did not want any of the men involved to say guns were used. However, during cross-examination by Simpson attorney Gabriel Grasso, McClinton acknowledged that in a statement to police, he did not say Simpson had asked the men to bring guns. But he added, "I carried a gun at the request of O.J. Simpson."
According to earlier testimony, Fromong and Beardsley were offering more than 600 Simpson-related items for sale, including ties Simpson wore during his criminal trial for the 1994 murders of his ex-wife, Nicole Brown Simpson, and her friend, Ron Goldman.
Simpson was acquitted after one of the most sensational trials in American history, but a civil jury later found him liable for their deaths, slapping him with a $33 million judgment. In the years since, attorneys for the Goldman family have doggedly pursued Simpson's financial assets to pay the judgment.
McClinton testified Tuesday that after seizing the memorabilia from Fromong and Beardsley, the men took the items to the parking lot of The Palms, where they loaded them into a white Infiniti SUV driven by an unidentified white man and woman.
He said Simpson told him that one of the footballs taken from the dealers could have been worth $50,000. E-mail to a friend