NORWALK, Conn. — Two former residents of a Maine treatment center where prosecutors say Michael Skakel confessed in 1978 to killing Martha Moxley testified Thursday about intimidation tactics staff members used to confront Skakel.

The two defense witnesses, Sarah Petersen of Florida and Michael Wiggins of South Carolina, said that one of Skakel's chief accusers at the Elan facilities was known for not being truthful and eager to turn in other residents in order to ingratiate himself with Elan staff.

The defense claims John Higgins, who testified for the prosecution last week, would not have hesitated to tell staff members if he had truly heard Skakel admit that he killed Martha with a golf club in 1975. Higgins, however, did not report Skakel's confession to school officials. He did not speak of the confession until investigators approached him in 1998.

The testimony of Higgins and other former residents of Elan, who say Skakel confessed to killing Martha while he was in a drunken state, is at the heart of the prosecution's circumstantial case.

Higgins testified last week that Skakel, a nephew of Ethel Kennedy, admitted during a long, emotional discussion about slaying that he "did it." Higgins told the court that the alleged admission came after Skakel initially said that he did not know what happened, then, that he could have done it, and finally, that he must have done it.

Petersen testified that she called defense lawyer Mickey Sherman after learning in 2000 that Skakel had been arrested and charged with Martha's murder. Petersen said she learned soon after arriving at Elan in January 1979 that Skakel was "shot down," which meant he had no status at Elan.

As punishment for running away from Elan, Skakel was made to wear a sign that stretched from his neck to the floor, she testified. "It said to confront him on the death of his friend," Petersen said.

The defense witness also recalled attending a general meeting of Elan residents, where Skakel was being screamed at by other residents. "When he was confronted about the killing of Martha Moxley, what would he say?" Sherman asked. "He said he did not do it," Petersen answered.

She said Skakel would then be placed in the "boxing ring." A group of residents stood around in a circle with their hands clasped as Skakel was pummeled, one at a time, by six or seven residents who wore boxing gloves and head gear.

"When he said, 'I don't remember. I don't remember,' that would get them to at least lay off them for a little while," she said. Petersen said the confrontation lasted six or eight hours before Skakel finally offered, "I don't know. I don't remember. Maybe I did."

Wiggins, who is on parole for a fraud conviction in the 1980s, offered similar testimony about the confrontational tactics used on Skakel. "Did he ever say, 'I did it?'" Sherman asked. "No," Wiggins said. "He said, 'No, I did not kill Martha Moxley.'"

Wiggins recalled that Skakel was made to wear two signs for three or four weeks. One sign said, "Confront me on why I killed Martha Moxley." The other sign said, "Please confront me on why I'm a spoiled brat," Wiggins testified.

The defense contends that if Skakel had truly confessed residents would have gone to staff members to report it because the nature of the program at Elan was that residents who conformed received privileges and status. Petersen told jurors that she would have told the school authorities if Skakel had made any admissions about the Moxley murder to her.

"I would have run to the staff because that's the way the program worked," she said. The trial is now in its 13th day.