Prosecutors said the schoolboy, who was 14 at the time, used a box cutter to brutally stab the 24-year-old, before using a recycling bin to take her body into the woods.
In finding 16-year-old Philip Chism guilty, the jury rejected the defense’s argument that he was suffering from a psychotic episode at the time of the 2013 attack and therefore not criminally responsible for his actions.
Chism was 14 when he committed the killing at his high school in Danvers, Massachusetts, but he was tried as an adult and could be sentenced to life in prison.
Prosecutors presented voluminous evidence during the month-long trial, including school surveillance videos, to support allegations that Chism followed his teacher, Colleen Ritzer, into a bathroom after school, strangled and raped her, and carted her body in a recycling bin to a wooded area off campus.
The trial at Essex County Superior Court in Salem, Massachusetts, was occasionally delayed by Chism, who at one point refused to return to the courtroom after a break telling his attorney that he was “about to explode.”