A prosecution psychiatrist agreed Tuesday that Charles McCoy Jr. (search), the man behind a series of shootings along highways around Columbus, was severely mentally ill, but he testified that the man understood it was wrong every time he fired his gun.

Attorneys for McCoy. concede he was behind the 12 shootings in 2003 and 2004 in which one woman was killed. Under his plea of innocent by reason of insanity, they must prove that his illness kept him from understanding the was against the law," Dr. Phillip Resnick (search) testified Tuesday for the prosecution.

Resnick, a psychiatry professor at Case Western Reserve University medical school in Cleveland, was called to the stand a day after a defense psychiatrist told jurors that McCoy could not have understood the shootings were wrong. McCoy, 29, was only trying to stop voices from telling him that he should stand up from himself, Dr. Mark Mills testified.

Resnick said he agreed with Mills that McCoy was acting out of anger and frustration and that the shootings would reduce the harassing voices in his mind. He said McCoy told him he stopped caring whether he hurt anyone because firing his gun helped soothe the voices.

However, Resnick said McCoy did several things that showed he knew the shootings were wrong.

For example, Resnick said, McCoy told him he would not shoot if an officer was close, and witnesses to the shootings said he left quickly after firing.

Resnick said McCoy also moved the scenes of his attacks to other freeways and counties once publicity and law enforcement scrutiny centered on the stretch of Interstate 270 near his home on the city's south side where the shootings began.

McCoy could face the death penalty if convicted of the most serious charge of aggravated murder in the death of Gail Knisley (search), the only person struck by a bullet.

Mills said Monday that McCoy believed satellites listened to his thoughts and that his television spoke directly to him, including a commercial that mocked struggles he'd had building a deck. The voices berated McCoy as a "wimp" and a "wuss" who wouldn't stand up for himself, Mills said.

Mills, a psychiatrist who specializes in legal aspects of mental illness, said McCoy has a severe case of paranoid schizophrenia but refused his medications because they had bad side effects — including body aches and diarrhea — and they interfered with his mind-reading ability.

McCoy would be sent to a mental hospital if jurors agree with the defense that mental illness kept him from knowing right from wrong.