NORWALK, Conn. – Despite defense challenges, a prosecution witness insisted Friday that Kennedy cousin Michael Skakel never left his Greenwich neighborhood the night Martha Moxley was beaten to death.

Andrea Shakespeare Renna, a friend of one of Skakel’s sisters, testified May 9 that Skakel did not go with his brothers to a cousin’s home, where the defense says Skakel was when Moxley was killed.

Skakel, 41, is on trial for murder, accused of beating Moxley to death with a golf club in 1975 when they were 15-year-old neighbors in an upscale, gated neighborhood of Greenwich.

On Friday, defense attorney Michael Sherman played a tape of a 1991 interview with investigators, trying to show Renna was less certain of Skakel’s whereabouts. On the tape, Renna says she assumed Skakel stayed behind with a brother, Thomas, Moxley and another neighbor girl.

“I didn’t see them leave, so I can’t tell you who was in that car,” she said on the tape.

Renna, who had been visiting one of Skakel’s sisters the night of the slaying, said Friday that even though she doesn’t remember seeing Skakel inside his house, she still doesn’t think he made the trip to his cousin’s.

Sherman pressed her on what made her so sure.

“My memory,” she responded.

Prosecutor Susann Gill also retested Renna on her recollection.

“Do you have an abiding conviction that Michael was at the home after the car left?” Gill asked, to which Renna replied: “Yes.”

Renna also testified that Skakel told her of the murder the following morning.

“Michael told us that Martha had been killed and that he and Tommy were the last to see her that night,” Renna said.

On Thursday, a former baby sitter who worked for Skakel’s relatives took the stand for the defense and testified that Skakel protected her during an alleged affair with Skakel’s cousin, Michael Kennedy. Skakel is a nephew of Robert F. Kennedy’s widow, Ethel Kennedy.

Marissa Verrochi, now 24, said she was 15 when Skakel befriended her. Skakel was identified as the main contact for prosecutors investigating Kennedy, who was never charged and later died in a skiing accident in Colorado.