Plaskon had to decide whether or not he would accept the deal or have the case go to trial.
Prosecutors said it's been nearly two years since Plaskon admitted to stabbing Sanchez to death in a hallway at Jonathan Law High School. Covered in blood, Plaskon allegedly told the school resource officer "I did it, just arrest me."
"The discussions in the case involve everything," said Edward Gavin, defense attorney. "I only know what he's been charged with at this point and that's what pre-trial discussions are about, anything and everything."
"He's charged with murder right now and there are discussions as there are in any case about what he'd plea guilty to and what the potential punishment would be," said Kevin Lawlor, prosecutor.
If Plaskon didn't take the deal, his case would have headed to trial with a three-judge panel sometime during the spring.
His lawyers said they prepared an insanity defense that cited their client suffered from a mental disease or defect when the murder occurred.
"Christopher has been evaluated by my experts as well as the state's experts and it will certainly factor into the discussion here, if not the primary factor. It's a consideration, no doubt," Gavin said.
Plaskon could face anywhere from 25 to 60 years in prison for the murder charge.
While Maren Sanchez's family declined to comment, wishing to save their statements for sentencing day, an attorney representing her father spoke outside of court, saying "Nothing that happened this morning is going to bring Maren back. That's a fact and nothing is going to stop the pain of losing a child."
Plaskon will be back in court on June 6, when he will officially be sentenced.
His attorney said he will likely stay at the Manson Youth Institute in Cheshire until he is 21 or 22 and then be transferred to an adult prison.
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