By waiving the hearing, which had been scheduled for Wednesday in suburban Pittsburgh, Alex Hribal and his attorney acknowledge prosecutors have enough evidence for Hribal to stand trial.
Defense attorney Patrick Thomassey didn't immediately return messages for comment on the filing. But Thomassey 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, Hribal faces decades in prison if he's convicted.
All the victims have been released from hospitals since the April 9 stabbings, the last one on May 17.
Thomassey must convince a judge that Hribal's prospects of rehabilitation are greater if the case is moved to juvenile court, where there is more emphasis on treating offenders and less on punishment. Thomassey has he would raise the matter of the boy's mental state before a judge determining whether the case moves to juvenile court. If the case isn't moved, Thomassey has said Hribal's mental state should still be considered as part of his criminal defense.
Thomassey has acknowledged Hribal took two eight-inch kitchen knives from his home and began stabbing students who had arrived at the school in Murrysville, about 15 miles east of Pittsburgh, but had yet to begin their first class of the day.
Get Breaking news, live coverage, and Latest News from India and around the world on NDTV.com. Catch all the Live TV action on NDTV 24x7 and NDTV India. Like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.