UPDATED: Teen Suspect Charged as Adult in School Stabbings

Police have identified and charged a 16-year-old boy accused of stabbing and slashing 21 fellow students and a security guard at a Pennsylvania high school.

Authorities say Alex Hribal was being charged as an adult following the Wednesday morning attack in Murrysville, 15 miles east of Pittsburgh.

He appeared before Magisterial District Judge Charles Conway and was charged with four counts of attempted homicide and 21 counts of aggravated assault. He was shackled by his hands and feet and was dressed in a hospital gown.

The teenager's family lives in a two-story home with an attached garage in a nice subdivision of large, newer homes there. No one answered the door or phone calls.

The FBI was at the house Wednesday night.

Neighbors say the teenager is the younger of the family's two boys.