HARTFORD, Conn. (AP) — Connecticut prosecutors plan to appeal the dismissal of Kennedy cousin Michael Skakel's murder conviction to the U.S. Supreme Court.

An assistant state's attorney notified the Connecticut Supreme Court of the planned appeal Tuesday.

The state Supreme Court earlier this month reversed its own 2016 decision and vacated Skakel's murder conviction in the bludgeoning death of Martha Moxley in their wealthy Greenwich neighborhood in 1975, when they were teenagers. The majority in the 4-3 ruling said Skakel's trial lawyer failed to contact an alibi witness.

Skakel is a nephew of Robert F. Kennedy's widow, Ethel Kennedy. A jury in 2002 convicted him and he was sentenced to 20 years to life in prison. He was freed in 2013 after 11 years behind bars when a state judge overturned his conviction.