A 16-year-old charged with stabbing 20 fellow students and a security guard at his high school outside Pittsburgh has waived his right to a preliminary hearing.

By waiving the hearing, which had been scheduled for Wednesday, Alex Hribal (RY'-bal) and his defense attorney acknowledge that Westmoreland County prosecutors have enough evidence for the case to proceed to trial.

Defense attorney Patrick Thomassey didn't immediately return messages seeking comment about the waiver he filed Monday. But he has said he plans to ask a judge to move the case to juvenile court, where Hribal would face incarceration or probation only until he's 21.

If the case remains in adult court, the former Franklin Regional High School sophomore faces decades in prison if convicted. All the victims have been released from hospitals.