The motive remains unknown as the suspect has refused to talk. Police say he has no prior record. They said they were searching the suspect's cellphone, school video footage and social media posts for any evidence of a possible motive. "The person that's got the most insight and the motive is not talking," said Bouchard, according to the Associated Press.
Undersheriff Mike McCabe said the suspect's parents visited their son where he's being held and advised him not to talk to investigators, as is his right. Police must seek permission from a juvenile suspect's parents or guardian to speak with them, he added.