(CNN) -- A 16-year-old Connecticut high school student suspected in the slashing death of a classmate was under emergency commitment at a medical facility, his lawyer said Saturday.
The classmate, Maren Sanchez, 16, who was described by her family as "a bright light full of hopes and dreams," died Friday after being slashed in a school stairwell, authorities said. She was cut in her neck, chest and face.
Though the motive is under investigation, police were looking into rumors the boy was angry because Sanchez had declined to go to the prom with him.
The alleged assailant was removed by staff members at Jonathan Law High School in Milford, local police said.
He was being held at a local medical facility and a murder charge is pending, officials said.
Attorney Richard Meehan said Saturday via e-mail that the suspect was under a 15-day emergency commitment and would not appear at an arraignment scheduled for Monday. Meehan would not elaborate.
He'll be arraigned in a juvenile court in New Haven, though police note that courts will decide later whether he will be tried as an adult.
The incident began around 7 a.m. in a stairwell at the school, and was witnessed in part by at least one school staff member.
Sanchez, a junior, suffered "multiple lacerations" and investigators "recovered a knife at the crime scene," police said. Morgan obtained the following
The Office of the Chief Medical Examiner in Connecticut concluded Saturday that 16-year-old Maren Sanchez died from "stab wounds to the trunk and neck" and ruled the death as a homicide.
School staff members and emergency technicians attempted "life-saving measures," according to Milford Police Chief Keith Mello, but Sanchez was pronounced dead at Bridgeport Hospital at 7:43 a.m.
Addressing reporters on Friday, the police chief didn't provide a motive but said investigators are looking into rumors that the boy was angry because Sanchez had declined to go to the prom with him.
The prom, scheduled for Friday night, was postponed. All students were sent home, and Milford Public Schools Superintendent Elizabeth Feser said counseling services will be available to them throughout the weekend.
On Friday, friends and classmates of Sanchez gathered around her prom dress and released balloons into the air. The balloons were violet, her favorite color.
On Instagram, classmates in prom attire posted images of themselves holding her green gown.
The slain girl's cousin, Edward Kovac, read a statement from her family lamenting what they called an "unprovoked attack" that ended the life of a young woman who had "her future at her fingertips."
"Maren should be celebrating at her prom this evening, with her friends and classmates," the family said, via Kovac. "Instead, we are mourning her death, and we are trying as a community to understand this senseless loss of life."
The family statement recalled other cases of school violence, saying "we can never forget the lessons ... from this" and other incidents. One of those incidents happened about 22 miles away, in December 2012 in Newtown, when a lone gunman shot his mother to death, then went to Sandy Hook Elementary School and killed 26 people, including 20 children, before taking his own life.
"We need to ensure that more young children are protected from violent attacks at school," the family said.
CNN's Ralph Ellis, Ray Sanchez and Haley Draznin contributed to this report.