New details have emerged in the slaying of a beloved Massachusetts high school math teacher.
Two law enforcement sources "close to the investigation" told CNN's Pamela Brown that 14-year-old Philip Chism used a box cutter to kill Colleen Ritzer.
Ritzer's body was discovered in a wooded area behind Danvers High School on Wednesday.
Authorities believe that Chism went to a matinee showing of the new Woody Allen movie, "Blue Jasmine," shortly after murdering Ritzer, the Boston Herald Reports.
Students told the Associated Press they were shocked that Chism could have killed the popular educator.
"From what I know about him and seeing him every day, it just doesn't add up that he would do such a thing, unless this was all an act to fool somebody," Ryan Kelleher, 17, said.
Ritzer was reported missing on Tuesday after she didn't come in to work, Essex District Attorney Jonathan Blodgett told the AP.
CNN reports that Chism was also reported missing on Tuesday night. He was found walking along a highway later that night.
His arrest was made "based on statements by the suspect and corroborating evidence at multiple scenes," according to court documents obtained by the AP.
Police have yet to release a motive for the killing.