(AP) - A 15-year-old Massachusetts boy accused of raping and killing his math teacher last year was indicted Friday on a second aggravated rape charge. A grand jury in Essex County indicted Philip Chism on a charge alleging that he forcibly had sexual intercourse with Colleen Ritzer, a teacher at Danvers High School. Chism, who was 14 when Ritzer was killed in October, was already charged with aggravated rape for allegedly sexually assaulting Ritzer with a stick. The 24-year-old teacher's body was found in woods near the school with her throat slit and a note that read, "I hate you all." Carrie Kimball Monahan, a spokeswoman for Essex District Attorney Jonathan Blodgett, said Chism may be arraigned on the new charge next week at a previously scheduled pretrial hearing. Chism's lawyer, Denise Regan, did not immediately return a call seeking comment. Monahan would not comment on the additional evidence presented to the grand jury, which was recalled Friday morning and handed down the indictment a short time later. "We had to wait until we had the evidence to present to the grand jury in order to do so," she said. Chism had moved to Massachusetts from Clarksville, Tenn., before the beginning of the school year. Students told police that Chism stayed after school to receive extra help the day Ritzer was killed. Search warrant documents made public describe surveillance video that authorities said show Chism following Ritzer into a school bathroom, wearing gloves and a hood. He is also allegedly seen pulling a recycling barrel through the school and outside. A recycling barrel was found near Ritzer's body.