Northern Illinois University police said the gunman in Thursday's campus shootings had stopped taking prescribed medications and had begun acting erratically in the days before he walked into a science lecture and opened fire, but his background didn't suggest he was a person likely to act in such a violent manner.

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Police said the suspect, identified as 27-year-old former student Steven Kazmierczak, killed five students, wounded at least 15 others and then killed himself.

"We had no indications at all this would be the type of person that would engage in such activity," University Police Chief Donald Grady said, without giving details. He described the gunman as a good student during his time at NIU, and by all accounts a "fairly normal" person.

It was reported that a sixth student had died Friday morning, but Coroner Rusty Miller told the media that there was a communication error between his office and the hospital.

Chris Larrison, an assistant professor of social work, said Kazmierczak did data entry for Larrison's research grant on mental health clinics. Larrison was stunned by the shooting rampage, as was the gunman's faculty adviser, professor Jan Carter-Black.

"He was engaging, motivated, responsible. I saw nothing to suggest that there was anything troubling about his behavior," she said.

Kazmierczak 'Outstanding Student'

Police have yet to uncover a motive. Kazmierczak was an NIU graduate student in sociology in the spring of 2007, but was not currently enrolled, according to a release on the school's Web site.

The Chicago Tribune reported that the school honored the gunman two years ago for his research on the U.S. prison system. The research included a study of self-inflicted wounds among prisoners.

"He was an outstanding student. An awarded student," said NIU Police Chief Donald Grady. "Those he had communication with felt he was a very good student and a fairly normal, unstressed person."

Grady said that Kazmierczak was a graduate student in social work at the University of Illinois at Urbana-Champaign. Kazmierczak was taking some kind of medication, Grady said, but declined to name the drug or provide other details.

"He had stopped taking medication and become somewhat erratic in the last couple of weeks," Grady said.

Kazmierczak had four weapons with him when he entered the lecture hall, according to Kevin Cronin of the Bureau of Alcohol, Tobacco, Firearms & Explosives: a Remington 12-gauge shotgun, a Glock 9 mm pistol, Sig Sauer pistol and High Point 380 pistol.

Cronin said that the shotgun and Glock were purchased legally at a gun shop in Champaign, Ill., on Feb. 9. Traces were being conducted on the other two guns.

University President John G. Peters said officials believe the shooter had no criminal record and had not been in contact with police prior to the shooting.

Scene Of The Shooting

Kazmierczak opened fire around 3 p.m. in an oceanography class inside an auditorium in Cole Hall. Police said the shooter did not fire all the ammunition he possessed.

Kazmierczak shot himself on the stage after a rampage that lasted just a few minutes and sent terrified students screaming, crying and running for the doors.

Journalism major Desiree Smith was at the back of the hall when the gunman opened fire. She said she dropped to the floor and kept telling herself, "Oh God, he's going to shoot me. Oh God, I'm dead."

Authorities don't know if the gunman targeted specific people or just shot at random.

Police said when the shooting was reported, officers were at the scene in "less than two minutes."

Victims Mourned

The students killed have been identified as: Daniel Parmenter, 20, of Westchester, Ill.; Catalina Garcia, 20, of Cicero, Ill.; Ryanne Mace, 19, of Carpentersville, Ill.; Gayle Dubowski, 20, of Carol Stream, Ill.; and Julianna Gehant, 32, of Meridan, Ill.

All of those shot were students, Peters said, including a graduate teaching assistant who was the class instructor and who was not killed.

More than 100 students cried and hugged as they held a candlelight vigil outside a fraternity house to mourn a sophomore who was among those killed. "Our hearts and prayers go out to the victims and their families," Peters said Thursday night. "We thank the community for the outpouring of sympathy during this terrible time of tragedy."

Peters urged students to remain calm and seek counseling.

"We've asked them to reach out to each other during this difficult time, and they've done that," Peters said. "And I'm proud of them."

The dean of students at the University of Wisconsin-Madison said the Illinois shooting "appears to be yet another terrible tragedy, this time affecting a nearby campus community."

"Our thoughts are with all of those affected and anyone on the UW-Madison campus from Northern Illinois," said Lori Berquam, Dean of Students.

The NIU Department of Public Safety is asking that any individuals who witnessed the Feb. 14 shooting, or who believe they have any information related to the shooting, call the University Tip Line at 815-753-TIPS. Police will return calls as soon as possible.

"I'm so please as we've seen our students and staff come together and deal with this tragedy," he said.

The NIU campus in DeKalb, about 60 miles west of Chicago, is closed Friday.