SALEM, Mass. (CBS/AP) — The trial of a Massachusetts teenager charged with killing his math teacher has been delayed after a judge ordered him to undergo a mental health evaluation.

Sixteen-year-old Philip Chism is charged in the October 2013 rape and killing of 24-year-old Danvers High School teacher Colleen Ritzer. He was 14 at the time but is being tried as an adult. He pleaded not guilty.

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Jury selection started this week and testimony was scheduled to start next Tuesday.

Over the past few days he has refused to enter the courtroom, banged his head against a floor and told a psychologist he hears voices and hopes someone will shoot him.

Prosecutors say he’s faking it to avoid trial.

Judge David Lowy on Thursday ordered an evaluation to determine if Chism is competent for trial, which could take 20 days. He will be evaluated at the Worcester Recovery Center and Hospital.

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He will be held in an adult locked unit, and won’t have access to any unsecured area in the hospital.

“I want to make sure that every effort that can be made is made to try and get this report done well, but as expeditiously as possible,” said the judge.

But Prosecutor Kate MacDougall doubts the exam will find Chism incompetent. She says he has a history of manipulating people to get what he wants.

“Even if we go 20 days, we’re going to be sitting here exactly where we are with the court ultimately in the position of having to make the determination,” she says.

WBZ NewsRadio 1030’s Bernice Corpuz reports

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