Kennedy cousin Michael Skakel made a tearful confession about the slaying of Martha Moxley when he attended a substance abuse treatment center in the 1970s, a former classmate testified Thursday.

John Higgins was one of three former students at the Elan School in Maine to take the stand at Skakel's murder trial. Under cross-examination, Higgins said he initially lied to an investigator by withholding information about the confession.

Skakel, 41, a nephew of Robert F. Kennedy's widow, is charged with beating Moxley to death with a golf club in their Greenwich neighborhood in 1975 when they were both 15. He could get life in prison if convicted.

Under questioning by prosecutors, Higgins described a prolonged and tearful confession that took place while he and Skakel sat together on a porch at Elan.

Higgins said Skakel told him about a party at his home and that he remembered going through some golf clubs in his garage. Skakel "related that he was running through some woods; he had a golf club in his hand. He looked up, he saw pine trees. The next thing he remembers is he woke up in his house," Higgins said.

Higgins said Skakel then made a "progression of statements" — first saying he didn't know whether he had killed Moxley and eventually saying "I did it."

Charles Seigan was the first of the former students to take the stand. He testified that Skakel told classmates he was drunk the night Moxley was beaten to death and that he did not know whether he killed her.

Seigan said Skakel's alleged involvement came up on several occasions. The first time was during a group meeting of about 90 people called to confront Skakel about running away from Elan, Seigan said.

Joseph Ricci, the school's director, "blurted out" the possibility that Skakel killed someone, Seigan said.

During smaller group meetings, Skakel would say he was drunk and had a blackout the night of the slaying, Seigan said.

"He would generally come to tears, shake his head and say, 'I don't know,"' Seigan said. "And there were other times when he was irritated with the questions."

Seigan described Elan as a "crazy place" where students were forced to take part in boxing sessions and publicly berate classmates.

Judge John F. Kavanewsky Jr. ruled prosecutors could present the written testimony of another Elan student, Gregory Coleman, who died last year after using drugs.

Coleman admitted during pretrial hearings that he was on heroin when he told a one-judge grand jury that Skakel confessed. But Coleman stuck by his statement that Skakel told him: "I'm gonna get away with murder. I'm a Kennedy."

Earlier Thursday, a former limousine driver for the Skakel family testified that Skakel once told him he had done something "very bad" and had to either kill himself or get out of the country.

Lawrence Zicarelli said that in 1977, Michael Skakel was crying during a trip to the doctor's office in New York City and apologizing for his behavior.

Skakel and his father, Rushton Skakel, had been arguing that morning, Zicarelli said. Once in the city, Michael bolted from the car, but Zicarelli said he found him walking toward the doctor's office.

"He had done something very bad, and he had to either kill himself or get out of the country," Zicarelli testified.

Zicarelli said he later asked Skakel what he had done that was so terrible. "He said if I knew what he had done, I would never talk to him again," Zicarelli said.

Zicarelli testified he gave two weeks' notice that day, and was immediately fired by Rushton Skakel.

On cross-examination, defense attorney Michael Sherman suggested Skakel may have been upset because he had slept in his dead mother's dress the night before. Sherman told reporters he misspoke in court. He said Skakel had the dress with him in bed but was not wearing it.