A boy leaves a flower outside Danvers High School in Boston, Massachusetts October 23, 2013. [Photo/Agencies]

DANVERS Mass.— A 14-year-old high school student described by classmates as soft-spoken and pleasant was accused of killing a well-liked math teacher, whose body was found in the woods behind the school.

Law enforcement officials recovered the remains of 24-year-old Danvers High School teacher Colleen Ritzer early Wednesday, Essex District Attorney Jonathan Blodgett said. The teen, Philip Chism, was arraigned Wednesday in Salem on a murder charge and ordered held without bail.

Ritzer was reported missing late Tuesday night after she didn't come home from work or answer her cellphone. Investigators found blood in a second-floor school bathroom and soon located her body, Blodgett said. He did not say how Ritzer died.

"She was a very, very respected, loved teacher," Blodgett said, calling the killing a "terrible tragedy."

The boy also was reported missing Tuesday after not coming home from school. He was spotted walking along a road in neighboring Topsfield at about 12:30 a.m. Wednesday.

Investigators said in court documents that the arrest was made based on statements by the suspect and corroborating evidence at multiple scenes. They said they also recovered video surveillance.

At his arraignment in adult court Wednesday afternoon, Chism's defense attorney argued for the proceeding to be closed and her client to be allowed to stay hidden because of his age. The judge denied the request. The attorney declined to comment outside court.

Ritzer had a Twitter account where she gave homework assignments, encouraged students and described herself as a "math teacher often too excited about the topics I'm teaching."