Florida teen's attacker mentally ill, not responsible, expert says

A psychiatrist says a Florida teenager was in the midst of a severe episode of mental illness triggered by a text message about his brother's suicide when he attacked and nearly killed a 15-year-old girl.

Dr. Alexander Neumeister of New York University testified Thursday that the text from victim Josie Lou Ratley to Wayne Treacy instantly changed his mental state. Neumeister says Treacy was suffering from post-traumatic stress disorder stemming from his brother's suicide a few months before the March 2010 kicking and stomping attack on Ratley ouside a middle school.

Neumeister says it's clear Treacy didn't know what he was doing. Treacy is claiming innocence by reason of insanity to attempted first-degree murder charges. If convicted he faces up to 50 years in prison.

Closing arguments could come Friday.