The murder trial of Philip Chism is disturbing on so many levels. The teenager is currently being tried in Salem on homicide and other charges stemming from the death of math teacher Colleen Ritzer in 2013 when Chism was just 14 years old.

First and foremost, the crime was horrific, involving a brutal attack in a school restroom and the callous discarding of the victim’s corpse in the woods. The premature loss of a much-beloved and devoted teacher who was only 24 years old has resonated throughout the Commonwealth.

Second, even though the trial judge has found Chism competent to stand trial, concerns linger about the defendant’s mental health: concerns triggered not just by his appalling actions two years ago but by his affect in the courtroom and reports from his lawyers about his deteriorating state of mind. Earlier this week Chism refused to return to the courtroom after a break because he claimed he was "about to explode" and fearful of what he might do.

The confluence of events in the Chism trial—a gruesome crime, a seemingly unstable defendant, and uncertainty about the future course of the legal proceedings—provides an opportune time to address a topic that has largely escaped notice so far. Should teenagers accused of murder ever be tried as adults and confront the prospect of a life sentence?

The Massachusetts Legislature passed a “youthful offender” statute in 1996 that created special categories of juvenile offenders aged 14 and older. For those accused of homicide, the legislation provided that the defendant would automatically be tried as an adult. This means that some juveniles may ultimately serve a life sentence in prison.

Several major punishment theories, including deterrence, retribution, and incapacitation, underlie this law. In the eyes of some supporters, the stiff penalty might deter would-be murderers from following through on their intentions; plus, it would impose a suitable punishment for the most blameworthy of crimes and thereby achieve a measure of retribution. A life sentence would also incapacitate a dangerous person, preventing him from harming others outside the prison gates.

In recent years, however, we have learned more about adolescent brain development. Research indicates that the portion of the brain that governs rational decision-making is not fully developed in human beings until their 20s. According to the National Institute of Mental Health, “[t]he parts of the brain responsible for more ‘top-down’ control, controlling impulses, and planning ahead—the hallmarks of adult behavior—are among the last to mature.” These findings call into question the very idea of holding juveniles fully responsible for their criminal transgressions.

In line with the implications of the science, the trend at the highest echelons of our legal system is to decrease juvenile sentences. In 2005, the Supreme Court ruled that executing prisoners who committed their crimes as juveniles was a cruel and unusual punishment in violation of the Eighth Amendment. In subsequent cases, the court banned life without the possibility of parole (“LWOP”) sentences inflicted on juveniles for non-homicide offenses, and determined that mandatory LWOP sentences for juveniles convicted of murder also ran afoul of the Eighth Amendment. The Massachusetts Supreme Judicial Court held in 2013 that the imposition of a LWOP sentence for juvenile offenders—whether mandatory or discretionary—was “unconstitutionally disproportionate.” The upshot in Massachusetts is that juveniles charged with murder may still face life sentences, although they are entitled to be considered for parole at some stage.

The larger issue is whether we should ever treat teenagers, even the most heinous of them, as adults for purposes of legal proceedings and criminal sentencing. Let’s return to the theoretical foundation for “being tough” on juvenile murderers: deterrence, retribution, and incapacitation. Will some, if any, teenagers be deterred from committing homicide through the threat of being tried as an adult given data suggesting that people in that age cohort often struggle with impulse control and advance planning as it is? And what about retribution, a theory predicated on the belief that the punishment should fit the crime, that the penalty should comport with the defendant’s level of blameworthiness? Is a 14-year-old who commits murder—even if it is a cold-blooded act unaffected by mental illness—as blameworthy as an adult? While incapacitation is served by locking up a juvenile potentially for life, is that a sufficient justification for such harsh sentencing practices? Finally, what about the expense?

We don’t let 14-year-olds do a lot of things. They can’t legally drink alcohol, smoke cigarettes, drive, vote, marry, and so on. Why? Because we consider them too immature to handle activities deemed to be the province of adults. But we let them stand accountable in open court as adults for the most serious of criminal charges. I don’t think that’s right.

Daniel S. Medwed is professor of law at Northeastern University and a legal analyst, WGBH News.