Lee Boyd Malvo, who at 17 plunged the capital region into terror through a series of random sniper style attacks he carried out with John Allen Muhammad, presents a difficult case for those who believe life sentences without the possibility of parole are inappropriate for those who were juveniles at the time of their crimes. His actions were depraved and horrific. They caused tremendous pain to the families of men and women who were gunned down at random throughout suburban Virginia and Maryland, and they struck fear into millions more.

Yet his case also exemplifies why such sentences are wrong. The Supreme Court has repeatedly recognized that juveniles cannot and should not be held to the same standards of culpability as adults because they lack the intellectual, emotional and moral development and because they are more prone to the influence of others. That last factor was profoundly apparent in this case.

Mr. Malvo was brainwashed by Muhammad, who was 41 at the time and offered him fantastic promises and justifications for his crimes. That doesn’t excuse Mr. Malvo’s actions or mean that he should not be held accountable for them. But it does mean that the criminal justice system should at least account for the possibility that Mr. Malvo could reform.

A federal judge in Virginia has already ruled that Mr. Malvo’s life sentences there need to be reconsidered based on Supreme Court rulings that occurred after his trials. The high court has found that life sentences without the possibility of parole are illegal for juveniles for any crimes except murder (not an issue in this case; Mr. Malvo was convicted on multiple murder counts) and that mandatory minimum sentences of life without parole are illegal for juveniles for any crime. Last year, the court decided that the standard should be applied retroactively to people serving such sentences. The court has also outlawed the death penalty for crimes committed by juveniles. (Muhammad was executed in Virginia in 2009.) Citing a 2012 Supreme Court ruling, the Virginia judge, Raymond A. Jackson, wrote that Mr. Malvo is entitled to have the courts consider whether his crimes are proof of “irreparable corruption” or the product of “the transient immaturity of youth,”

It is by no means likely that Mr. Malvo will be freed, at least not anytime soon. Virginia authorities are appealing that decision, and even if it holds up, Mr. Malvo could be re-sentenced for life. He is also implicated in killings in several other states, where he could still be prosecuted. And he has already been sentenced to six consecutive life sentences without the possibility of parole in Maryland.

Arguments seeking to overturn those sentences took place yesterday in Montgomery County. It’s not clear whether they present as strong a legal case as those in Virginia because the life-without-parole sentences here were not mandatory. Yet the case against such terms for juveniles remains the same.

Mr. Malvo is clearly not the same person he was when he committed his crimes.

The boastful, remorseless boy has become a young man who understands the pain he caused. Five years ago, he told the Washington Post, “I was a monster. If you look up the definition, that’s what a monster is. I was a ghoul. I was a thief. I stole people’s lives. I did someone else’s bidding just because they said so. ... There is no rhyme or reason or sense.” We aren’t prepared to say whether Mr. Malvo deserves a second chance in life, but we believe the criminal justice system should be forced to at least consider the question for him and all others who commit crimes before they become adults.