The 16-year-old suspect, who was charged as a juvenile offender, will not appear at an arraignment scheduled for Monday in New Haven, attorney Richard Meehan said.
The teenager is accused of fatally stabbing Maren Sanchez, 16, in the hallway of Jonathan Law High School in Milford. The attack occurred Friday morning, hours before the school's junior prom, and authorities were investigating whether Sanchez was stabbed after turning down the suspect's invitation to the dance.
The victim's cousin, Edward Kovac, said Friday in a statement on behalf of the family that they are shocked and devastated. He said Sanchez was "a bright light full of hopes and dreams with her future at her fingertips."
Meehan said the suspect's family is also reeling from the attack.
"His family is devastated not only for him, but the youngster who was killed. It's a terrible situation all the way around," Meehan said.
The suspect could be charged as an adult, but he would need to appear in court for that to happen. State's Attorney Kevin Lawlor said several factors go into that decision, including the seriousness of the charges.
The commitment of the suspect can last for up to 15 days, according to Meehan. He said doctors typically order such involuntary commitments in cases where a suspect is considered a danger to himself. Meehan said the defense expects to waive a detention hearing Monday in juvenile court.
Police said they were looking into reports from students that the suspect had asked Sanchez to prom and were examining whether a rejection prompted the attack, but they have not offered a motive for the slaying.
"It's all being investigated," Officer Jeffrey Nielsen, a spokesman for Milford police, said Saturday. "We don't work off speculation. We work on facts."
Sanchez, a member of the National Honor Society who was active in drama and other school activities, had been focused on prom in the days before she was killed. She had posted on Facebook a photograph of herself wearing a blue prom dress and was looking forward to attending with a new boyfriend.
At school Thursday, Sanchez and a friend talked excitedly about their plans for the upcoming dance.
"We were just laughing, talking about what we were going to do when we got there, how many pictures we were going to take," said the friend, Imani Langston.
That night, she was helping to paint the set for a high school production of "Little Shop of Horrors" when she asked to be excused to have her nails done, drama adviser Michael Mele said.
"So here is this girl with her freshly painted prom nails, painting the set, and just having a great time with her classmates talking about plans for the prom and plans for after prom and going on a double date with another one of the drama kids and her new boyfriend," Mele said.
The dance has been postponed indefinitely and students instead gathered Friday night for a candlelight vigil, with counselors on hand for anyone who needed them.