Pennsylvania officials sought a motive on Thursday for a stabbing rampage at a high school where a 16-year-old student was accused of wielding two knives and wounding nearly two dozen people.
The attacker stalked through Franklin Regional High School in Murrysville near Pittsburgh on Wednesday, stabbing victims in the torso and slashing their arms and faces with 8-inch steel blades before being tackled by an assistant principal, officials and students said.
Sophomore Alex Hribal was taken into custody and charged with attempted homicide and aggravated assault, Murrysville Police Department Captain Rob Liermann said.
The teen had no psychiatric or disciplinary problems, and his family described him as a good student who mingled well with others, family lawyer Patrick Thomassey said in television interviews.
"He was not a loner," he told CNN on Thursday.
Thomassey said he met with Hribal for 20 minutes before his arraignment on Wednesday, but could not identify a motive.
"We're trying to figure that out," Thomassey told CNN. "This is a nice young boy. I mean, nobody would expect this. This is not a dysfunctional family. They're like the 'Brady Bunch.' His parents are active with their two sons."
Hribal's parents were horrified and sent their condolences to the victims and their families, he said.
Hribal was charged as an adult, but Thomassey told CNN he would try to move him into the juvenile court system.
Twenty-one students and a security officer were stabbed in the incident, said Dan Stevens, a spokesman for Westmoreland County emergency management.
While the United States has seen a series of large-scale shootings in public places in recent years, including schools, movie theaters and shopping areas, mass stabbings are less common.
Police and the FBI on Wednesday searched the suspect's home. Neighbors said both parents work, and the teen has a brother who also attends Franklin Regional High School.
The high school will be closed, probably until Monday, while police conduct an investigation, officials said.
Murrysville Police Chief Tom Seefeld told CNN that authorities were investigating a report of a threat made the night before the stabbings, but had no evidence to support that.
The victims were aged mostly 14 to 17 years.
Among the most seriously injured was a 17-year-old boy, who remained in critical condition at UPMC Presbyterian hospital early Thursday following surgery, a hospital spokeswoman said. A knife had passed through his liver, diaphragm and some major blood vessels, but missed his heart and aorta.
The knife missed the boy's heart and aorta by millimeters, said Dr. Louis Alarcon, director of trauma surgery at UPMC Presbyterian, where the boy was being treated. He was on breathing machines and sedated, Alarcon said at a news conference.
"Patients who are stabbed in the abdomen and chest by definition have life-threatening injuries," said Chris Kauffman, director of trauma at Forbes Regional Hospital, where some of the injured were treated.
At least seven other teenage boys were recovering overnight in two other hospitals
On Wednesday evening, community members held candlelight vigils for the wounded.
Hribal faces four counts of attempted homicide and 21 counts of aggravated assault, police said. He was ordered to face a preliminary hearing in seven to 10 days.
'Screaming bloody murder'
Freshman Josh Frank said he did not initially realize that anyone had been stabbed, but fled when he heard screaming.
"He did it so stealthily that at first no one knew what was happening," Frank said. "We heard a girl scream bloody murder. Then two seniors were running down the hall and we followed them out of the school."
The attacker used a large knife, based on the wounds suffered by at least one of his victims, said a doctor who had operated on a 17-year-old student with a large chest wound.
"Apparently it was a large knife of some sort, because it was a large injury to his abdominal wall and went through his liver, diaphragm and major blood vessels," said Dr. Louis Alarcon of the University of Pittsburgh Medical Center.
Doctors also said a female student helped save a male schoolmate by applying pressure to his wound until emergency responders arrived.
"She displayed an amazing amount of composure to help that friend who was having pretty significant bleeding at that point," said Dr. Mark Rubino, of Forbes Regional Hospital.
One apparent student victim, Nate Scimio, posted a widely circulating selfie from the hospital of himself in a gown, smirking and pointing to a bandage on his forearm.
Reuters and the Los Angeles Times