(CNN) -- A 16-year-old Connecticut high school student suspected in the slashing death of a classmate was charged with murder as an adult Tuesday.
The victim, 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 remains under investigation, police were looking into whether the boy was angry after Sanchez rejected him as a prom date.
The suspect, Christopher Plaskon, was taken into custody Friday by a school police officer in the principal's office. His clothing and hands were bloodied.
"I did it," Plaskon allegedly told the officer, according to a probable cause statement filed with a Milford court Tuesday. "Just arrest me."
The Jonathan Law High School student, who remains under emergency commitment at a medical facility, was ordered held on $3 million bond.
During a special court session convened at the medical facility, Plaskon's lawyer, Richard Meehan, Jr., said his client had been advised of his rights and told that he was being charged with murder as an adult. He faces 25 to 60 years in prison if convicted.
Meehan said in a statement that Plaskon "is in need of continued psychiatric care and medication and should be housed in an age-appropriate correctional center when he is released from the emergency commitment." Plaskon is to be formally arraigned Friday, provided he is released from the emergency psychiatric hold.
In a statement Tuesday, Plaskon's family said words could not convey "the raw sadness we are left with by this unimaginable tragedy. Our hearts are forever broken."
The statement continued: "To the Sanchez family, our deepest sympathies. Please know that you are now, and forever, in our hearts, our thoughts and our prayers. We join with the entire Milford community to celebrate the life and mourn the loss of this most vibrant and exceptional young woman. To our extended family, friends and neighbors and all who have reached out to us in our darkest hour with warmth, kindness, understanding and compassion, you cannot know how much it has meant to us. Thank you."
The fatal slashing occurred about 7 a.m. Friday in a school stairwell. A witness saw Plaskon on top of the victim and tried unsuccessfully to pull him away, according to the probable cause statement. Another witness allegedly saw him discarding a bloody knife in a school corridor.
Sanchez, a junior, suffered "multiple lacerations," police said.
The state medical examiner's office concluded Saturday that Sanchez had died from "stab wounds to the trunk and neck" and ruled the death 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.
The prom, which was scheduled for the night of the slaying, was postponed. All students were sent home, and counseling services were made available throughout the weekend.
On Friday, friends and classmates of Sanchez gathered 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 prom 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 statement said. "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 Newtown, where 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 in December 2012.
"We need to ensure that more young children are protected from violent attacks at school," the family said.
In their statement, the Plaskon family said, "In prayer we ask for comfort for the Sanchez family and all of us so deeply affected by this tragedy. We pray for the wisdom to guide us as we desperately try to pull together the shattered pieces of our families. And finally, we pray that time may soften our wounds and reveal forgiveness in the hearts of all."
CNN's Lena Jakobsson contrinuted to this report.