MILFORD, Conn. (CBSNewYork/AP) — A judge on Tuesday ordered a Connecticut teenager accused of fatally stabbing a classmate on the day of their junior prom to be examined by a psychiatrist hired by the state, after his lawyers announced they were pursuing an insanity defense.

Christopher Plaskon, 17, appeared Tuesday in Milford Superior Court. He is charged with murder in the slaying of 16-year-old Maren Sanchez in a hallway at Jonathan Law High School in Milford in April 2014.

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The attack occurred hours before the school’s junior prom, and police have been investigating whether it was related to Sanchez’s refusal to be Plaskon’s date.

A witness saw Plaskon on top of Sanchez during the attack and tried unsuccessfully to pull him away, and another saw him discard a bloody knife, according to a police affidavit.

Plaskon, his clothes bloody, was taken to the principal’s office, where an officer arrived and asked what happened. “I did it. Just arrest me,” Plaskon replied, according to the officer.

Judge Frank Iannotti approved a motion by Milford State’s Attorney Kevin Lawlor to allow the prosecution to have its own expert evaluate Plaskon’s mental health and continued the case to July 7. The order came after Plaskon’s lawyers filed notice Monday that they were planning a defense of “mental disease or defect and/or extreme emotional disturbance.”

Lawlor indicated in court documents that the state would hire a Yale University forensic psychiatrist.

Richard Meehan, an attorney for Plaskon, said experts hired by the defense examined Plaskon, but he declined to say what they found. Meehan has said Plaskon was taking anti-psychotic medication and anti-anxiety medications.

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“The focus here is on mental status,” Meehan said after the court proceeding.

Plaskon, who is charged as an adult, faces up to 60 years in prison with a mandatory minimum of 25 years if found guilty of murder.

If found not guilty by reason of insanity, he could be detained for 60 years at the state’s maximum-security psychiatric hospital in Middletown or possibly released years earlier if doctors determine he is no longer a danger to himself or others.

Plaskon pleaded not guilty last year and chose a trial before a three-judge panel instead of a jury.

Anthony Bonadies, a lawyer for Sanchez’s father, Jose Sanchez, attended the court hearing Tuesday while his client was in Florida.

“Mr. Sanchez — is committed to stay the course to make sure that Maren’s life is front and center during the proceedings,” he said. “She needs to remain in the hearts and minds of whoever the decision-makers will be, so there’s accountability for her death and justice.”

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