US

Police search for motive of high school stabbing rampage that injures 22

  • Parents and students embrace along School Road near Franklin Regional High School after more than a dozen students were stabbed by a knife wielding suspect at the school on Wednesday, April 9, 2014, in Murrysville, Pa., near Pittsburgh. The suspect, a male student, was taken into custody and is being questioned. (AP Photo/Tribune Review, Sean Stipp)  PITTSBURGH OUT

    Parents and students embrace along School Road near Franklin Regional High School after more than a dozen students were stabbed by a knife wielding suspect at the school on Wednesday, April 9, 2014, in Murrysville, Pa., near Pittsburgh. The suspect, a male student, was taken into custody and is being questioned. (AP Photo/Tribune Review, Sean Stipp) PITTSBURGH OUT  (The Associated Press)

  • CORRECTS SPELLING OF LAST NAME TO EGYUD, NOT EGYUND, AND HER TITLE TO CHIEF NURSING OFFICER - Forbes Hospital President Chief Medical Officer Dr. Mark Rubino, center, addresses the media as vice president and chief nursing officer Amber Egyud, left, and Forbes Hospital President and CEO Reese Jackson listen in during the second morning news conference at at the hospital Wednesday, April 9, 2014, in Monreoville, Pa. Two student stabbing victims from Franklin Regional High School in Murrysville, Pa., were in critical condition, according to Rubino. Forbes Regional Medical Center is closest hospital to the school where eight victims were taken. (AP Photo/Tribune Review, Evan Sanders)  PITTSBURGH OUT

    CORRECTS SPELLING OF LAST NAME TO EGYUD, NOT EGYUND, AND HER TITLE TO CHIEF NURSING OFFICER - Forbes Hospital President Chief Medical Officer Dr. Mark Rubino, center, addresses the media as vice president and chief nursing officer Amber Egyud, left, and Forbes Hospital President and CEO Reese Jackson listen in during the second morning news conference at at the hospital Wednesday, April 9, 2014, in Monreoville, Pa. Two student stabbing victims from Franklin Regional High School in Murrysville, Pa., were in critical condition, according to Rubino. Forbes Regional Medical Center is closest hospital to the school where eight victims were taken. (AP Photo/Tribune Review, Evan Sanders) PITTSBURGH OUT  (The Associated Press)

What motivated a stabbing rampage at a Pennsylvania high school remains a mystery, with the teenage suspect's attorney calling him a good student who got along with others.

Sixteen-year-old Alex Hribal (RY'-buhl) faces dozens of charges, including four counts of attempted homicide, in the stabbing attack that injured 21 students and a security guard at Franklin Regional High School outside Pittsburgh. He's jailed without bail.

Police say Hribal used two kitchen knives to attack students up and down a hallway. At least five students were critically wounded, including a boy who was on a ventilator after a knife pierced his liver.

Students say Hribal was quiet and shy and largely kept to himself.

Defense attorney Patrick Thomassey has asked for a psychiatric examination.