Meet Teen High School Student Who Bruttaly Raped and Killed His High School Math Teacher Inside Restroom '

Chilling new surveillance video showing a high school teacher's last moments of life was played in court Wednesday during the trial of the teen accused of raping and murdering her. Jurors watched video in court from the surveillance cameras at Danvers High School, Massachusetts, that caught what prosecutors say is Philip Chism, then 14, following Colleen Ritzer in the hallway.

Chism, now 16, has pleaded not guilty to murder, rape and other charges in the October 2013 slaying of 24-year-old Ritzer, a math teacher at the high school. The video first shows Ritzer, sporting a smile and a purple top with black pants as she waves to someone who isn't on camera, walking alone down a hallway at the school.

Moments later, Chism, in a blue hooded sweatshirt, can be seen leaving a classroom to follow her. With the hood of the sweatshirt over his head and gloves on, the chilling footage then shows the teen, who was 14 at the time, enter the restroom that Ritzer is in.

A few minutes later, a female student then can be seen walking into the bathroom, but she quickly exits.

Prosecutors have explained previously that the girl saw a male's bare buttocks and that she left giggling because she thought she walked in on someone changing their clothes, the Boston Herald reported.

Another clip shows Chism with his hood still raised, walking swiftly down a hallway carrying clothing in his arms, including what appears to be the teacher's black pants that she was seen wearing prior to entering the restroom.  In the footage, the teen's right hand is visibly red, from what could be the teacher's blood.

Jurors in the trial also saw the recycling bin that prosecutors say Chism used to move Ritzer's body to the woods just outside of Danvers High School. 

While heading to the restroom at the school, Ritzer (left) is followed by a teen said to be Chism

The Herald reported that Chism showed no reaction to the video, staring straight ahead from his seat at the defense table.

Prior to playing the video in court, Judge David Lowy spoke to Chism about whether he wanted to be in the courtroom during the proceedings, WCVB reported.

The teen refused to return to court Tuesday, when he told his lawyer, Denise Regan, he was 'about to explode and ... doesn't want to hurt anyone.'

She said that the math teacher had a consistent routine and came home every day at 3.30pm.

When she didn't that day, the family at first thought she had made other plans or been in an accident. They began to worry when she wasn't home for dinner, wasn't answering her cellphone and hadn't posted on Facebook. They tried contacting her friends and other teachers.

teacher Colleen Ritzer

Her husband went to the high school and found his daughter's car still in the parking lot.

'At that point we started to get very upset,' Peggie Ritzer said.

Jury selection was delayed several weeks while Chism underwent a competency evaluation.  (Dailymail)