Updated 6:21 PM ET
CHARDON, Ohio - The teenage suspect in an Ohio school shooting that killed three students and wounded two told investigators he didn't know his victims and chose them randomly, a prosecutor said Tuesday.
Suspect TJ Lane, 17, admitted firing 10 shots with a .22-caliber pistol Monday morning at Chardon High School, Geauga County prosecutor David Joyce said at a juvenile court hearing.
The hearing came hours after the death toll rose to three, and as schoolmates and townspeople grappled with the tragedy and wondered what could have set the gunman off.
Lane's face twitched lightly while the prosecutor recounted the attack, and he sniffled and half-closed his eyes as he walked out of the room with deputies.
Lane's custodial grandfather and two aunts joined him in court; the women reached over and lightly embraced the grandfather as the hearing began.
Judge Timothy Grendell ordered the boy, who is considered a juvenile, held for at least the next 15 days. Prosecutors have until March 1 to charge him.
The judge imposed a gag order on opposing attorneys at the prosecutor's request and told the media not to photograph the boy's face in court. He is a juvenile.
"Given his age and the nature of the allegations against him," said CBS Radio News legal analyst Andrew Cohen, "he'll almost certainly end up being tried as an adult -- and jurisdiction over the case will soon transfer over to adult court. Clearly the judge who presided over this early hearing was under that impression.
He added: "Even though Ohio has a death penalty Lane would not be eligible for capital punishment if he were to be convicted of murder here -- the Supreme Court precluded that sentencing option for people who are under 18 when they murder."
CBS News correspondent Bob Orr reported that "Lane has told investigators he stole the gun he used from his uncle, who had legally obtained it. Sources say in fact there were lots of legal guns around. About two dozen weapons were discovered in FBI searches of Lane's relatives' homes."
Demetrius Hewlin, a student from Chardon High School, and who was previously listed in critical condition,, becoming the third fatal victim of the shooting.
Shaken residents offered condolences and prayers to the families of those killed and wounded at 1,100-student Chardon High School in suburban Cleveland. All three of the dead were students, as are the two people wounded.
"This gets more tragic, the whole area is suffering, our prayers go up to God to give all strength, healing and closure," said one of hundreds of Facebook postings on a memorial page.
The community offered grief counseling to students, staff and others at area schools.
"We're not just any old place, Chardon," Chardon School Superintendent Joseph Bergant II said. "This is every place. As you've seen in the past, this can happen anywhere, proof of what we had yesterday."
News of Hewlin's death came after another student, Russell King Jr., was declared brain dead, authorities said Tuesday. The Cuyahoga County Medical Examiner's Office received the word about King Jr. just before 1 a.m. Tuesday, office administrator Hugh Shannon said in a statement. It was unclear whether King remained on life support; the statement referred to him as both deceased and brain dead.
King, 17, was one of five students injured when a suspect identified by a family lawyer as Lane began shooting at Chardon High School Monday morning. King was studying alternative energy at nearby Auburn Career Center and like the others who were shot was waiting for a bus for his daily 15-minute ride to the center. Student Daniel Parmertor died hours after the shooting.
Both King and Parmertor were students at the Auburn Career Center, a vocational school, and were waiting in the Chardon High cafeteria for a bus for their daily 15-minute ride when they were shot.
The police chief would shed no light on a motive.
"I feel sorry not only for that family but all the families that are affected by this," McKenna said. Characterizing himself as a "hometown boy," he added: "Chardon will take care of Chardon."
A student who saw the attack up close said it appeared that the gunman targeted a group of students sitting together and that one of the dead was shot while trying to duck under the cafeteria table.
Lane's family is mourning "this terrible loss for their community," attorney Robert Farnacci said in a statement.
Lane did not go to Chardon High, instead attending nearby Lake Academy, which is for students with academic or behavioral problems.
Fifteen-year-old Danny Komertz, who witnessed the shooting, said Lane was known as an outcast who had apparently been bullied. But others disputed that.
"Even though he was quiet, he still had friends," said Tyler Lillash, 16. "He was not bullied."
Farinacci, representing Lane and his family, told WKYC-TV that Lane "pretty much sticks to himself but does have some friends and has never been in trouble over anything that we know about."
Student Nate Mueller said that he was at the table in the cafeteria where the victims were shot, and a bullet grazed his ear.
"My friends were crawling on the floor, and one of my friends was bent over the table, and he was shot," Mueller told The Plain Dealer. "It was almost like a firecracker went off. I turned around and saw (Lane) standing with a gun and I saw him take a shot."
Mueller told the Cleveland newspaper that Lane would wait at the school to take a bus to Lake Academy. Mueller said that King one of those killed had recently started dating Lane's ex-girlfriend.
Lane "was silent the whole time," Mueller said. "That's what made it so random."
Frank Hall, an assistant high school football coach who students say chased the suspected gunman out of the cafeteria, told a Cleveland TV station that he couldn't discuss what happened, but added: "I just want to say that I'm sorry for the families."
Hall told WEWS on Tuesday that school staffers had been asked by the district to be sensitive about the investigation.
"I wish I could have done more," said Hall, whom students have hailed as a hero.