A 14-year-old Cleveland student, who shot and wounded four people before killing himself Wednesday, had been suspended for fighting two days earlier and was not supposed to be on campus, school officials say.
Classmates say he warned of retaliation after the suspension, but no one took him seriously.
The student, identified as Asa H. Coon, had a history of mental problems and was known for using profanity when speaking to teachers and bickering with students.
It's not clear why he was allowed into the school.
"When he got suspended, he was like 'I got something for you all,'" classmate Frances Henderson said. "I guess this is what he had."
Classes at all Cleveland public schools were canceled today.
At a morning press conference, Cleveland Police Chief Michael McGrath provided some details about how the shooting occurred. Coon entered the school and went to a fourth floor bathroom, McGrath said, where he changed clothes and likely retrieved .22-caliber and .38-caliber revolvers from a duffel bag. Police later found the bag and a change of cloths in the bathroom.
Coon then went to a specific fourth floor classroom where he shot a targeted teacher, McGrath said. He continued in search of a second teacher, McGrath said, and instead shot at another teacher who confronted him in the hallway, as well as fellow students.
The shooting victims were identified as two male teachers and two male students. Three of the victims were taken to the Metro Health Hospital. Already, one of the teachers and one of the student victims have been released. The other teacher, shot in the chest, underwent surgery and is expected to recover.
The other student -- a 14-year-old male -- was shot in the side and transported to Rainbow Babies & Children's Hospital, where he was in stable condition, Jackson said. A 14-year-old female student injured her knee trying to flee from the shooter. Both reportedly are in good condition.
While Coon may have shot specific teachers, it was unclear if the two students were targeted victims or random bystanders. Student Jeremy Rivers told ABC News that it appeared Coon "didn't care who he was shooting. He was crazy."
The Cleveland Plain Dealer newspaper reported that Coon had been in juvenile detention facilities two times and had threatened to commit suicide. McGrath said today that police had been to Coon's house five times since 2006 to respond to a range of incidents. Coon was arrested in 2006 after a "domestic disturbance" at his home.
McGrath said that Coon's older brother and mother will be interviewed and will specifically be asked about the guns used in the shooting, which the chief described as "older" weapons.
'A Real Angry Kid'
David Kachadourian, 57, the math teacher shot by Coon in the hallway, told ABC News that he did not realize at first that he had been shot, and he took some students and hid in a closet, before realizing he was bleeding.
Kachadourian, who had Coon as a student, said he saw him waving two guns and yelling just before he was shot. He knew Coon was troubled. "He did behave in a way that suggested he was angry, yes. He seemed like a real angry kid," he said.
The AP reported that the fight that predicated his suspension was about God. He told a student he did not believe in God, but worshiped goth rock star Marilyn Manson.
Coon reportedly liked to wear trench coats and paint his fingernails black, an eerie reminder of the students behind the infamous Columbine High School massacre.
Kachadourian told "Good Morning America" today that he could not think of an incident that would make him a target, but said that as one of Coon's teachers, "I suppose it was possible."
Coon fatally shot himself after opening fire shortly after 1 p.m. EDT on the fourth floor of SuccessTech Academy, a nontraditional public school in the city's downtown area. The two handguns, a box of ammunition and three knives were recovered from Coon's body or near him. Police believe a total of eight rounds were fired.
Coon shot himself after peering out a window, according to McGrath. It's possible, McGrath added, that the student gunman saw police show up at the school before he shot himself once in the head. "The suspect did not have any weapons in his hands. They were laying next to his body," he said.
The specialized school, funded in part from a grant from the Bill and Melinda Gates Foundation, was one of the last places many would expect a shooting like this to occur.
On its Web site today the Gates Foundation posted the following statement about the shooting: "This is a tragedy that underscores for all of us how precious each young person's life is. We have reached out to education leaders in Cleveland to express our condolences and support during this difficult time. This reminds us of the complexity of our work together but only deepens our commitment to our goals."
Kachadourian, however, said the school, which was designed to give individual attention to promising poor students, had begun to change.
"When it began, the class size was supposed to be no more than 15 students," he told "GMA." Now Kachadourian said his "smallest class has 30 kids and his largest has 40."
Since October 2006, there have been 15 incidents reported to the Cleveland Police Department at SuccessTech, McGrath said. One involved a BB gun.
There was an armed security guard at the front desk at 1 p.m. Wednesday, around the time the shootings began. McGrath confirmed there are no metal detectors at the school.
Maureen Harper, a spokesman for Cleveland Mayor Frank Jackson, said that the head of the city's public schools would review how the district identifies problem students and "how we handle red flags." The review will also include the type of metal detectors and other devices used to secure buildings. A plan will be presented Friday to the mayor who will then make it public.
ABC's Aaron Katersky in Cleveland and The Associated Press contributed to this report.