A former cellmate of Richard Lee Earman testified at Earman's Arlington murder trial yesterday that Earman told him he had killed Alan Foreman and Donna Shoemaker last May after Foreman supposedly cheated some of Earman's alleged Mafia connections of $20,000 worth of cocaine.

Larry G. Piper Jr., 30, said he only came forward with the information on Thursday, although he said Earman had told him last July that he committed the murders. Originally, Piper had been scheduled to testify only that Earman had told him that he had last seen the couple alive after returning with them the night of their murders from the Georgetown discotheque Tramps.

Piper testified at the Arlington Circuit Court jury trial that he had been reluctant to come forward with the expanded version of his testimony because he was "scared to death" of what would happen to him if he divulged it. He decided to come forward at the last minute, he said, because "I don't want Lee Earman back on the streets because I know what he did."

Foreman, 26, an Arlington real estate agent, and his fiancee, Shoemaker, 25, were found May 8, shot to death in Foreman's yellow Jaquar in the garage of his home at 1201 N. George Mason Dr. in Arlington.

Piper, who is serving concurrent six-year sentences for armed Fairfax, said that Earman also told him that he was good friends with Ray Moore Tugwell Jr., a prosecution witness, and, like Earman, a convicted burglar, and James L. Breeden, convicted killer of four men in a Fairfax Roy Rogers Restaurant. Breeden is currently serving four life sentences for the murders in addition to a 20-year sentence for shooting a fifth person who was also in the restaurant.

Piper said that Earman described himself. Tugwell and Breeden as "rap partners since we were kids." Under questioning by Assistant COmmwealth's Attorney Helen Fahey, Piper described rap partners as "buddies best pals . . . in jail. It's usually people who pull time together or have been involved in criminal activities together."

According to Piper, Earman told him that "Breeden killed all those people at the Roy Rogers, I killed Foreman and his girlfriend, and I keep wondering when they're going to get Tugwell." Piper said that Earman was not implying that Tugwell had committed any crimes for which he had yet to be arrested.

Piper said that Earman told him that while he had served a prison sentence, he had "met a lot of Mafia people" and that Earman said that he had maintained contact with them since he had been released from prison and returned to the Washington area.

Earman had been convicted of being part of a "Beltway Burglars" gang that allegedly committed more than 5,000 break-ins in the Washington area.

Piper testified that Earman told him that Earman's "Mafia connections" frequented Tramsp and Coco's Restaurant in Arlington. He said that Earman also told him that "Alan Foreman had ripped these people off for $10,000 worth of coke and that Alan Foreman, was a big cocaine dealer."

Piper said that Earman told him that he killed Donna Shoemaker because "she was there and could identify him."

Unded cross examination by Earman's attorney, John K. Zwerling Piper denied that he had come forward with his testimony in order to get a reduction in his own sentence or to gather publicity for himself.

Piper also said that he had committed the robberies for which he had been convicted because of his addiction to heroin, but said under cross-examination that he was not forced for lack of money to commit the robberies in order to pay for his habit.

His parents, Piper told Zwerling, would have paid for his heroin, but he said, "I was heaving problems breaking away from my parents and I didn't want to be dependent on them."