LAS VEGAS -- A lawyer said one of the co-defendants in the O.J. Simpson armed robbery case has agreed to plead guilty to a reduced charge and testify against Simpson and four others.

Interactive | Slideshow | Survey

Charles Cashmore's lawyer, Edward Miley, told The Associated Press that Cashmore will plead guilty Monday to being an accessory to robbery, a felony that could get him up to five years in prison.

A court clerk confirms that a court hearing is scheduled.

Simpson and five others, including Cashmore, are charged with kidnapping, armed robbery, assault, burglary and conspiracy in the Sept. 13 encounter with two sports memorabilia dealers in a Las Vegas hotel room.

The kidnapping charge carries the possibility of life in prison if convicted. Simpson, 60, faces an 11th felony charge, coercion.

Miley said Cashmore has agreed to testify that two other men who entered the room with Simpson were armed.

The lawyer for another of Simpson's co-defendants said the prosecution went overboard with the kind of charges they laid upon the former football star and the others.

Bill Terry is the attorney for Michael McClinton, who faces the same armed robbery, kidnapping and other counts Simpson does.

He said the kidnapping allegation "is fairly thin," and suggested that the challenge to the kidnapping case will be that the incident took place in a single hotel room and a kidnapping charge suggests people are being moved against their will.

In an interview with The Associated Press, Simpson said that he went to the room to get memorabilia that belonged to him, but he said he didn't break in. He also told the AP that no weapons were used.

Simpson said that he was conducting a "sting operation" to collect his belongings when he was escorted into the room at the Palace Station casino.

A memorabilia collector who claims to be the victim in the casino told the Web site TMZ.com that Simpson and two men came into his room to take the suit that Simpson wore when he was acquitted for murder.

The man, Alfred Beardsley, also told TMZ that two men who were with Simpson pulled guns upon entering the room.

Simpson's account is similar to a Las Vegas television station KVVU interview with a man, Thomas Riccio, who claims to have witnessed the incident that sparked the allegations.