Autopsy: NIU shooter didn't take illegal drugs before attack

The man who killed five students and wounded 16 in a Valentine's Day rampage at Northern Illinois University apparently did not have illegal drugs in his system at the time.

The body of Steven Kazmierczak, 27, had trace amounts of nicotine, cold medicine and a generic form of Xanax, an anti-anxiety drug his girlfriend had said a psychiatrist prescribed, according to autopsy findings released Friday,

The former NIU sociology graduate student -- once respected by many teachers and friends -- shot himself to death after raining bullets on a lecture hall filled with students Feb. 14.

The DeKalb County coroner said in a statement Friday that the shooter died from a gunshot wound to the mouth that fractured his skull and lacerated his brainstem. The coroner declined to provide additional information.

NIU Police Chief Donald Grady said Friday that the investigation has not turned up any clues that point to a motive for the assault. In the last month, he said investigators have been able to work through most of the necessary interviews with scores of witnesses and the shooter's friends and family.

Still, he said the investigation is pressing on and an end is not near. Authorities don't believe the shooter had an accomplice or let anyone know of his intentions.

"We are going to be working on this a while," Grady said.

The shooter had a history of mental illness -- he was committed after high school to a group home -- but he also was able to graduate from NIU with a bachelor's degree and pursue graduate work in sociology.

Friends and family say the shooter was acting normal in the days leading up to the rampage.

The gunman apparently made an attempt to cover his tracks before walking into Cole Hall wearing all black and carrying three handguns and a shotgun hidden in a guitar case. Grady has said the gunman hid the hard drive to his laptop and a computer chip to his cell phone.

The shooter spent a few nights in a hotel room near campus before the assault. Investigators found it littered with empty cigarette packs, energy drinks and cold medicine.

Meanwhile, there were troubling signs from the shooter in the months leading up to the assault. For one, he started stockpiling weapons and covering his body in bizarre tattoos, including one of a deranged clown riding a tricycle through a pool of blood.

He also stopped taking prescribed medication a few weeks before the assault because it made him feel odd, his girlfriend has said.

Jessica Baty, 28, of Wonder Lake said her boyfriend was on three medications: Xanax, for anxiety, Prozac, for depression, and Ambien, for insomnia.

The shooter stopped taking at least the Prozac about three weeks before the shootings, Baty has said. It is not clear if he stopped taking the other drugs as well.

The coroner characterized the level of generic Xanax in the shooter's body as "residual." After he quit his medication, his behavior changed, authorities say.

"My information is that he was behaving erratically -- he was angry and more prone to outbursts," Grady has said.

The gunman was raised in Elk Grove Village, but his family has since moved elsewhere -- his sister to Champaign and his father to Florida. His mother died in 2006 after suffering from ALS.

The shooter excelled as a sociology grad student at NIU in 2006 and was known by friends and professors as a stable man who wanted to work in the criminal justice field. He transferred with his girlfriend to the University of Illinois in the summer of 2007 to continue pursuing a graduate degree in social work. While there, he focused on mental health and prison issues.

The shooter's body was cremated at an Elk Grove Village funeral home without a service the week following the shooting.