Updated

A 15-year-old Massachusetts boy charged with killing his math teacher has been indicted on a second aggravated rape charge.

An Essex County grand jury on Friday accused Philip Chism of forcibly having sexual intercourse with Danvers High School teacher Colleen Ritzer.

Chism previously pleaded not guilty to murder, aggravated rape and armed robbery charges related to Ritzer's death. That rape charge stemmed from allegations Chism sexually assaulted Ritzer with a stick.

District Attorney Jonathan Blodgett's office recalled the grand jury to present additional evidence Friday. The grand jury then indicted Chism on the second rape charge.

A spokeswoman for Blodgett said Chism could be arraigned on the new charge next week.

Chism was 14 when Ritzer was killed in October. His lawyer did not immediately return a call seeking comment.