MURRYSVILLE, Pa. (AP) -- Detectives believe a boy charged with stabbing 21 other students and a security guard at his Pittsburgh-area high school threatened two students by phone before the attack.
The reference to the threatening phone messages and completed calls is contained in a search warrant affidavit. Westmoreland County District Attorney John Peck says neither student was among the victims in Wednesday's attack at Franklin Regional High School.
County detectives got the warrant for the home of Alex Hribal (RY'-bal). He is charged as an adult with four counts of attempted homicide and 21 counts of aggravated assault.
Hribal's attorney and the district attorney did not return messages seeking comment.
Four students are still hospitalized, three in critical condition. The fourth was upgraded to fair condition Monday.
Teachers returned to the school Monday but classes don't resume until Wednesday.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
Teachers on Monday attended a counseling session at a church and then returned to a high school where a student stabbed 21 others and a security guard last week, but they scuttled plans to march the half block between the two to avoid the media.
Monday's activities were the start of a three-day effort to reopen Franklin Regional High School for the first time since a boy attacked fellow students with a pair of kitchen knives last Wednesday.
On Tuesday, students and parents will get a chance to see that bloody hallways have been cleaned up and other steps taken to return the school to normal. Classes resume on Wednesday.
Four students were still hospitalized in critical condition Monday as the teachers gathered with two crisis counselors hired by the district. To avoid television cameras, the teachers drove to the school's parking lot or made the short walk up a wooded hill between the church and the 1,200-student school.
Two parents who chatted with reporters Monday, said their children were eager to get back to school.
"That's where he wants to be, to be with his friends," Jeff Mauro said of his son, Jamie, a ninth-grader who witnessed some of the stabbings. "This has been a learning experience that we have to love each other - all of us."
Laura Thompson said her children "seem to think they're going to be fine. But I think it's going to be different when they're back in that environment."
Alex Hribal, 16, is charged with four counts of attempted homicide and 21 counts of aggravated assault in the stabbings.
His attorney, Patrick Thomassey, didn't return calls and an email seeking comment, but he told the Pittsburgh Post-Gazette that he plans to waive Hribal's right to a preliminary hearing next week.
Once that happens, Thomassey will ask a Westmoreland County judge to move the case to juvenile court, a move prosecutors are expected to contest. Thomassey said that request will be based largely on a mental health evaluation by a doctor he's hired.