Raleigh, N.C. — A Virginia attorney said he plans to file a motion Wednesday seeking a new trial for Durham novelist and convicted killer Mike Peterson.

Jason Anthony, who practices in Richmond, Va., said prosecutors withheld evidence during Peterson's 2003 murder trial, violating a judge's order in the case and the state's laws regarding evidentiary discovery in criminal trials.

Peterson was convicted of first-degree murder in the Dec. 9, 2001, death of his wife, Kathleen Peterson. She was found dead in a pool of blood at the bottom of a staircase in the couple’s Forest Hills mansion.

Kathleen Peterson died of blunt force trauma to the head, according to an autopsy report. Mike Peterson, 64, has maintained his wife died in an accidental fall.

Anthony said Peterson's former attorneys didn't know that a neighbor found a tire iron in his yard shortly after Kathleen Peterson's death and turned it over to police. Prosecutors tested the tire iron but never shared the information with the defense attorneys, he said.

Knowing about the tire iron would have changed the defense considerably – it might have been the murder weapon – and likely would have discredited some witnesses, Anthony said.

Durham County District Attorney David Saacks couldn't be reached Monday for comment. He has said in the past that investigators determined the tire iron was irrelevant to the Peterson case.

Saacks also has said discovery rules in effect in 2003 were different than those now on the books.

Mike Peterson is serving a life sentence at Nash Correctional Institution. Last November, the state Supreme Court upheld his conviction.