A Massachusetts teenager's confession to police that he killed his math teacher cannot be used in his murder trial, a judge ruled Tuesday even as he allowed a bloody box cutter and other key pieces of evidence to be admitted. The ruling came in the case of 16-year-old Philip Chism, who has pleaded not guilty to raping and killing 24-year-old Danvers High School teacher Colleen Ritzer on school grounds in October 2013. Chism's lawyers had argued that police coerced their client, then 14, into making detailed statements about the killing, despite invoking his right to remain silent. Prosecutors maintained Chism and his mother had never absolutely demanded a lawyer.Philip Chism, now 16, helped investigators locate Collen Ritzer's body after her death in October 2013Judge ruled Tuesday that a taped police confession is now not admissiblePolice coerced Chism - then 14 - to confess when he wanted to remain silent, defense attorneys saidItems seized from Chism after arrest, including Ritzer's credit cards, a bloody box cutter and women's underwear, are allowed to be used at trialChism has deined raping and murdering the 24-year-old teacher
He also allowed items gathered at Danvers High School, as well as those seized from _'s pockets and backpack.