Authorities: Kazmierczak died of gunshot wound to mouth

DEKALB, Ill. -- The gunman who opened fire inside a Northern Illinois University lecture hall died from a "contact-range" bullet wound to the mouth, according to partial autopsy results released Friday by the university.

Steven Kazmierczak, 27, also had trace amounts of alprazolam, the generic name for the anti-anxiety drug Xanax, cold medicine and nicotine in his bloodstream when he fatally wounded five students before shooting himself on Valentine's Day, the school said. Eighteen other people also were wounded.

NIU officials said the DeKalb County coroner found that four of Kazmierczak's five victims died from gunshot wounds. No cause of death was given Friday for the fifth victim, who died at a hospital in neighboring Winnebago County.

"This is the extent of the information we are presently able to make available for public dissemination," school administrators said in a statement.

Police found empty cigarette cartons, cold medicine and energy drinks inside a DeKalb motel room where Kazmericzak paid cash for a three-night stay before the attack. Authorities have said he stopped taking antidepressants several weeks before the attack.

They still don't know what prompted Kazmierczak, who had transferred from NIU to the University of Illinois in 2007, to return to the DeKalb campus of 25,000 students or why he targeted an undergraduate geology class inside Cole Hall before turning the gun on himself.

Kazmierczak completed his undergraduate work at NIU, where he excelled in his studies of sociology.

Cole Hall, a massive lecture complex at the center of campus, has been closed since the attack and its future is uncertain.