In this Oct. 23, 2013, file photo, Philip Chism, 14, stands during his arraignment for the death of Danvers High School teacher Colleen Ritzer, as his attorney Denise Regan speaks on his behalf in Salem District Court in Salem, Mass. (AP Photo/Boston Herald, Patrick Whittemore, File)
BOSTON (AP) - Police say a Massachusetts teen admitted killing the 24-year-old math teacher whose body was found in the woods near the school in October.
Philip Chism is accused of raping and killing Danvers High School teacher Colleen Ritzer after she asked him to stay after school for help. The 15-year-old has pleaded not guilty to charges of murder and aggravated rape.
In search warrant documents for Chism's phone, state police say Chism admitted killing Ritzer but denied having sexual contact with her.
State police say they want to examine Chism's phone because it is not unusual for people involved in sexually violent homicides to memorialize the deaths "for further humiliation of the victim."
Ritzer's body was found with her throat slit and a note reading, "I hate you all."
(Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)