SALEM, Mass. -- Surveillance video from inside a Massachusetts high school shows a student following a math teacher before he allegedly killed her inside a women's restroom, CBS Boston reports. Philip Chism, 16, is charged with raping and murdering Colleen Ritzer in 2013. He was 14 at the time. The video, shown in Essex Superior Court in Salem on Wednesday, shows Chism following Ritzer to the restroom and pacing back and forth outside the door. He later emerges with the hood of his sweatshirt still covering his head. Jurors also first saw the large recycling barrel allegedly used by Chism...