ERIE — A co-defendant in the bizarre collar-bomb death of a pizza deliveryman in an Erie bank robbery says he is mentally incompetent to stand trial.

Kenneth Barnes' lawyers filed the motion on Monday.

Meanwhile, Marjorie Diehl-Armstrong, another co-defendant, is undergoing a mental evaluation. She says she will likely be found incompetent to stand trial. She told the Erie Times-News that the findings could be made official by Friday.

In August 2003, Brian Wells robbed a PNC Bank near Erie. He told police he had been forced at gunpoint to wear a bomb around his neck and rob the bank. The device exploded, killing Wells.

Diehl-Armstrong is in prison for killing her boyfriend. Prosecutors say she killed him so he could not tell authorities about the bank robbery plot.

By Associated Press