27-year-old Stephen Kazmierczak was once a good student
at Northern Illinois University. (CCTV.com)
Thursday's rampage happened at Northern Illinois University, where authorities said one of those injured in the attack has now died in hospital.
The Illinois shooting was the latest in a spate of attacks at US schools and universities.
32 people died at Virginia Tech last April when a South Korean student opened fire on fellow classmates before fatally shooting himself.
Upsound: " Hi I'm Steve. Can't think of anything clever to say right now."
27-year-old Stephen Kazmierczak was once a good student at Northern Illinois University.
But less than one year after his graduation, he became the campus' worst nightmare on Thursday, shooting dead six people before turning the gun on himself.
Don Grady, Niu Police Chief, said, "We have talked to people who were close to him and apparently he had stopped taking his medications and he had become somewhat erratic in the last couple of weeks."
Early police investigations show that Kazmierczak was carrying three handguns when he ambushed a lecture hall.
Two of the weapons - a pump-action Remington shotgun, and a Glock handgun - were purchased legally less than a week before the shooting.
Police recovered 48 shell casings and six shotgun shells. Witnesses say the gunman paused to reload his shotgun after firing on a crowd of around 160 students in a geology class.
Three people were killed at the scene and three more died in hospital. Another student remains in critical condition.
The investigation is on-going, with the motive still unclear.
Robert Kazmierczak, Father of Alleged Shooter, said, "Please leave me alone. I have no statement to make and no comment, Ok. I'd appreciate that. This is a very hard time. I'm a diabetic and I don't want to go into a relapse."
The campus of the century-old University remained closed on Friday.
Hohn Peters, Presidnet of Northern Illinois University, said, "We did everything we could to ensure the safety of this university and we are going to continue in that vein."
But for 25,000 students trying to come to terms with the tragedy, their campus nightmare will stay with them forever.
