Authorities and defense attorneys on Monday refused to provide details about the status of the 16-year-old teenager accused of fatally stabbing a high school classmate hours before their junior prom.
Meanwhile, the community of Madison, Conn., where the attack at Jonathan Law High School took place on Friday, made plans to mourn honor student and athlete Maren Sanchez, 16, at an evening vigil.
Authorities are investigating whether the attack on Sanchez, who was stabbed in the neck and torso, was related to whether she turned down the boy's invitation to the dance.
The suspect's attorney, Richard Meehan, said his client is being held in a hospital under psychiatric evaluation. Meehan said earlier Monday the teen would not appear at an arraignment scheduled in New Haven, though he later declined to provide comment to FoxNews.com about the teen's status, or whether the arraignment had taken place.
Plaskon is being charged with murder as a juvenile. However, Meehan told the Hartford Courant that he expects the teen's case will be transferred to Superior Court in Milford, where he will be charged as an adult.
Meehan has said the suspect's family is 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.
Mark Robinson, a technical education teacher, said Plaskon is the third of five brothers and has a good sense of humor. His family has deep roots in the community, Robinson said.
"There's no reason to suspect he would have done this," Robinson said. "I think that's what makes it harder."
Classmate Imani Langston, who saw Plaskon being read his rights and taken away in a police car, said Sanchez and the boy were just friends and had never dated.
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 her death. She had posted a photograph on Facebook of her blue prom dress and was looking forward to attending with a new boyfriend.
On Friday, students gathered to remember Sanchez at a local beach wearing the dresses and tuxedoes they were planning to wear at the dance, the Hartford Courant reported. They held Sanchez' dress up for a group photo and said they would name her their prom queen.
The school remained closed Monday.
A memorial service is scheduled for 7 p.m. Monday on the school's football field. A memorial fund for Sanchez has also been created and donations can be sent to the Maren Sanchez Memorial Fund, in care of attorney Mike McCabe, 23 Sunnyside Court, Milford, Conn. 06460.
FoxNews.com's Cristina Corbin, Karl de Vries and The Associated Press contributed to this report.