Chilling surveillance footage of 14-year-old Phillip Chism following his 24-year-old math teacher Colleen Ritzer was shown in court on Friday before jurors.

Chism, who is charged with his teacher's murder, is shown in the video clip following Ritzer into the women’s restroom. Chism spent several minutes in the bathroom before exiting with blood on his clothes. 

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The footage presented to the court by the prosecution team shows it was recorded on Oct. 22, 2013 – the day Colleen Ritzer was raped and killed at Danvers High School. 

Chism’s defense team isn’t denying any of the evidence in the video. Instead, they are claiming Chism was mentally disturbed when he decided to rape and murder his teacher.

RELATED: Defense admits Chism murdered teacher, claims he was mentally ill