A lawyer for Michael Skakel is seeking to keep the government from using audio tapes made by the Kennedy cousin for a memoir as evidence in his upcoming murder retrial.

Skakel, the nephew of Robert F. Kennedy’s widow, Ethel, was freed from prison last year after a judge ruled his trial attorney failed to adequately represent him in 2002 when he was convicted of fatally bludgeoning Martha Moxley in Greenwich when they were both 15.