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PITTSBURGH (KDKA) — The young man who allegedly went on a stabbing spree at Franklin Regional High School is reportedly planning to admit his guilt more than three years after the attack.

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Alex Hribal‘s attorneys notified the court about his decision on Monday, and the plea is expected in court Tuesday at 9 a.m.

KDKA’s Marty Griffin talked to Hribal’s attorney and the Westmoreland County District Attorney, and both confirmed the guilty plea.

Hribal once turned down a deal that would have required him to spend 30 to 60 years in prison.

Pat Thomassey, Hribal’s attorney, says he is disappointed his client was not able to plead guilty to being “mentally ill,” which would have committed him to a mental institution along with prison time.

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So, he took the weekend and decided to take his chances in front of a judge.

Hribal, facing 21 counts of attempted murder and aggravated assault, is accused in the brutal knife attack on 20 students at Franklin Regional High School in April of 2014. He was just 16 at the time.

He’s been in jail or a treatment facility since then.

Once Hribal pleads guilty to the attempted murder and aggravated assault charges, it will take around three months before an actual sentence is handed down.

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Meanwhile, Thomassey says Hribal has benefitted greatly from mental health treatment.