HARTFORD, Conn. — Kennedy cousin Michael Skakel's lawyers have filed a new appeal of his murder conviction, claiming that police and prosecutors failed to provide them with evidence that pointed to another suspect and discredited a key state witness.

The motion filed Thursday in U.S. District Court in New Haven seeks a hearing and the setting of bail. A judge has not ruled on the requests. Skakel, a nephew of Robert Kennedy's widow, Ethel, also has several other appeals pending.

A state jury convicted Skakel in 2002 of killing Martha Moxley in their Greenwich neighborhood in 1975, when both of them were 15. He's serving 20 years to life in prison.

His new appeal alleges his lawyers were never given two crucial pieces of evidence, including statements by a lawyer who said a key witness for the state, Gregory Coleman, had a history of lying.

The state Supreme Court upheld Skakel's conviction in January 2006, rejecting defense arguments including claims that Skakel was charged long after the statute of limitations in effect in 1975 expired, and that his case should have been tried in Juvenile Court.

The U.S. Supreme Court declined to review the case in November 2006, but Skakel has several other appeal claims pending in state and federal courts.

Fairfield County State's Attorney Jonathan Benedict, who prosecuted Skakel, declined to comment on the new court filing Friday. He said he hadn't seen the motion.

Story continues below

In the new motion, Skakel lawyers Hubert Santos and Hope Seeley say that they learned just two months ago that yet another man had been implicated in 1993 in Moxley's killing.

The allegation came from a woman who claimed her mentally ill brother, Andrew Wilson, had threatened another Greenwich family and named that family's son as Moxley's killer.

Wilson, who has been diagnosed with paranoid schizophrenia, was later convicted of killing the father of the man he had accused _ just weeks after her sister had raised those concerns.

"It would be a surprise to me if it was accurate," Robert Skovgaard, Wilson's attorney, said of the latest claim related to the Moxley murder.

At Wilson's murder trial, witnesses testified that Wilson had become delusional and said the victim's family ruined his life through mind control and drugging. Wilson is currently serving a 30-year prison sentence.

Courts have already rejected defense efforts to implicate two other men in Moxley's killing.

As for Coleman, the defense attorneys say that a lawyer named John Regan told them last month that he had told a state prosecutor years ago that Coleman was an "incorrigible drug addict who would routinely lie in order to get money for drugs."

It said Regan was "disturbed" that prosecutors had made his claims a key part of their case against Skakel.

Coleman, who attended a reform school in Maine with Skakel in the late 1970s, had claimed Skakel confessed to killing Moxley and said he would get away with murder because "I'm a Kennedy." Coleman admitted to being high on heroin during his grand jury, though. He died in 2001, but his testimony was read into the record during Skakel's trial.