Teen charged with killing his math teacher uses insanity defense

Philip Chism was 14 years old when he allegedly raped and murdered his math teacher in Massachusetts. Why did his lawyers turn to the insanity defense?

In this Nov. 4, 2015, photo, Philip Chism, left, appears in Salem Superior Court where a judge declared the Massachusetts teenager charged with raping and killing his math teacher competent to stand trial, in Salem, Mass. Chism's lawyers plan to make opening statements Monday, Nov. 16, 2015.

(Ken Yuszkus/The Salem News via AP, Pool, File)

November 16, 2015

Opening statements were presented Monday morning in Essex County Superior Court in Massachusetts in a trial of 16-year-old Philip Chism, who is accused of raping and murdering his 24-year-old math teacher, Colleen Ritzer, in October 2013.

Chism is being tried as an adult in Salem. His mental state will be the key issue in the trial, with his lawyers using a mental health defense to argue that Chism isn’t criminally responsible for Ms. Ritzer’s death, reported Reuters.

“Why did a 14-year-old boy, a well-behaved, quiet boy one month into high school do these terrible things?” Chism's attorney Denise Regan asked, reported Boston.com. “The answer is he was severely mentally ill.”

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According to CBS News, insanity defenses rarely succeed in Massachusetts, but Chism's young age might help convince jurors of a mental health defense.

"I assume the defense will tie it into research on adolescent brain development, in particular, adolescents have a difficult time calculating the future and having a sense of the ramifications on their future lives," Daniel Medwed, a law professor at Northeastern University, told CBS last month.

Chism told a psychiatrist hired by his defense team that “voices” drove him to kill his Danvers High School algebra teacher, according to a review by the Salem News of court papers filed by the prosecution last week.

Though Chism has pleaded not guilty to charges of first-degree murder and aggravated rape, the teenager allegedly confessed to the murder in a videotaped interview after the attack, telling police that the teacher provoked him with a "trigger" word that he did not identify.

But prosecutors won't be allowed to use Chism’s confession in court, reported CBS, as Superior Court Judge David Lowy ruled that Chism did not fully understand his constitutional rights before he spoke to police.

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As The Christian Science Monitor reported, the insanity defense is seldom successful, particularly in a jury trial. “If as a defense attorney you start off with a sympathetic victim and an unlikable defendant, you’re in a hole no matter what defense you’ve got,” says Bob Dekle, a University of Florida law professor and former prosecutor. “In general, insanity is a desperation defense. You haven’t got anything else, so you play crazy.”

Jane Campbell Moriarty, editor of “Mental Illness in Criminal Trials,” said in a Monitor interview ... that the US justice system has long struggled to incorporate new findings and frontiers in neurological science into understanding the nature of crime. In part, that divide largely explains why insanity defenses are raised in less than 1 percent of criminal trials. That’s despite the fact that a 2006 Bureau of Justice Statistics report found that about half of all US inmates, or 1.3 million, suffer from some form of mental illness.

Prosecutors allege Chism slashed the throat of Ms. Ritzer in a school bathroom on Oct. 22, 2013, when he was 14. He is also accused of sexually assaulting her.

Chism has also been charged as a juvenile for two counts of aggravated rape and armed robbery, according to Reuters.

If found guilty of first-degree murder, he would face a mandatory sentence of life in prison without the possibility of parole.

Recent legislation passed in many U.S. states makes it easier to try juvenile offenders as adults, according to PBS, the idea being that young offenders of violent crimes should receive sentences that are more proportional to their crimes and that the harsher punishment will deter other juvenile crimes.

PBS reports that there’s limited evidence showing whether harsher punishment is an effective deterrent to juvenile crime, though so far it points to minimal crime prevention and higher rates of reoffending.