Accused triple murderer Adam Mau-Goffredo has been indicted on new assault charges for allegedly trying to stab a prison guard in the eye with a pen in September 2006.

Mau-Goffredo was found incompetent to stand trial in the triple murder case earlier this year because he suffers from mental illness.

His lawyer, Brook Hart, expressed disbelief today when told of the new charges against his client.

"He was in the middle of a psychotic episode" when the alleged assault on the prison guard occurred, Hart said.

"It left a little mark next to the bridge of (the guard's) nose," Hart said. "I can't imagine how the interest of the government is advanced by charging a very sick man with these new offenses."

Mau-Goffredo was being held at the time at Oahu Community Correctional Center, charged with murdering Manh Nguyen and married couple Jason and Colleen Takamori July 6 2006, at the Tantalus lookout parking lot.

He was transferred to Hawaii State Hospital in February for treatment and medication after a three-member panel of experts found he was incompetent to stand trial because of mental illness.