Connecticut's highest court was hearing arguments Wednesday on whether Kennedy cousin Michael Skakel should get a new trial or be sent back to prison for a 1975 murder.

State prosecutors asked the state Supreme Court to reinstate the 2002 murder conviction against Skakel in the bludgeoning death of Martha Moxley when they were teenage neighbors in wealthy Greenwich.

Skakel, a nephew of Robert F. Kennedy's widow, Ethel, was freed on $1.2 million bail in 2013 when a lower court judge ordered a new trial after finding that Skakel's trial attorney failed to adequately represent him. He had been sentenced to 20 years to life in prison.

Skakel, 55, was seated in the gallery of the courtroom for the hearing, as was his cousin Robert F. Kennedy Jr.

Judge Thomas Bishop ruled that Skakel likely would have been acquitted if his trial lawyer, Michael Sherman, had focused more on his brother Thomas Skakel. Sherman has defended his work on the case.

Prosecutors are appealing Bishop's decision to the Supreme Court.

Thomas Skakel was an early suspect in the case, because he was the last person seen with Moxley and admitted he had a sexual encounter with her.

But prosecutors have said that highlighting Thomas Skakel's relationship with Moxley would have bolstered their argument that Michael Skakel killed her in a jealous rage.