The Boston Bomber Got The Death Penalty -- But Is He Too Young To Die?

'Virtually every murder committed by someone under age 25 was committed by someone who was not emotionally healthy,' one expert tells MTV News.

Dzhokhar Tsarnaev is going to die. Not today, not tomorrow, probably not for many years, but the 21-year-old Boston Marathon bomber will likely be put to death by lethal injection, after the long appeals process has played out.

And while there's no question about his guilt -- Tsarnaev's lawyer didn't attempt to prove his then 19-year-old client didn't join his now-deceased older brother, Tamerlan, in planting deadly bombs at the Boston Marathon finish line on April 15, 2013 -- the question that does remain is this: Is it fair?

Can You Condemn Someone Whose Brain Isn't Fully Formed?

Is it fair to apply the death penalty -- in a state that hasn't executed anyone since 1947 -- to a young person whose brain might have betrayed him as much as his convictions did on that day? MTV News put that question to Nita Farahany, a professor of law and philosophy at Duke University.

"Since there's an understanding that adolescence is a passing phase a person grows out of -- and most crimes are committed by males 18 to 35, and then crime rates drop drastically -- is it fair to execute a person who, 10 years later, will be drastically different?" Farahany replied. "That's a much harder question."

Tsarnaev in jail five months after his arrest.

Farahany, who was not directly involved in the Tsarnaev case, but is a leading scholar on the ethical, legal and social implications of bioscience and behavioral genetics, told MTV News that neuroscience can't necessarily offer a clean, clear answer to the fairness question. "In general, whether it's juveniles or adults, there's a difficulty in applying the death penalty fairly and consistently in a way that doesn’t seem arbitrary," she said.

Then again, Tsarnaev's crime -- an attack that killed three and seriously injured 240 -- feels like one of those rare cases that the death penalty is reserved for. But Farahany thinks we have to ask a deeper question about not just the crime, but the criminal.

The Teenage Brain Complicates Things

Neuroscience studies have shown that the frontal lobe of the brain is still developing until at least your mid-20s. That's significant, because Farahany said an increasing number of court cases have relied on science to argue that the young brain is missing key components when it comes to decision-making and impulse control.

The neurons in your brain have a protective, insulation-like coating around them called Myelin. Just like insulation protects pipes from freezing, Myelination protects your brain and decreases the noise inside of it and, Farahany explained, the less insulation you have in your frontal lobe, the less you can process information like an adult or protect your brain from potentially dangerous input.

"The frontal lobe impacts judgment and the ability to make independent and well-reasoned choices," she said. "That means you're likely to take risks, particularly ones where you can show off or try to impress other people and there was a lot of that behavior you saw in this case."

The use of neuroscience evidence in trials has increased nearly five-fold since 2005, Farahany added. In fact, Tsarnaev's lawyers tried to explain his actions by saying the 19-year-old was under the sway and influence of his older brother, who they pegged as the mastermind of the plot.

"When you have an extreme case like this, that kind of science can be factored into what influenced his behavior," she said. "But plenty of 19-year-olds are not going around doing horrific crimes even at the urging of their bother."

How Do We Really Feel About Putting Young People To Death?

While the Supreme Court has ruled it unconstitutional to put anyone under the age of 18 to death, there is still a squeamishness about capital punishment for young people like Tsarnaev. The parents of 8-year-old bombing victim Martin Richards wrote an essay in the Boston Globe, arguing against it in this case.

Not for forgiveness' sake, but for their own sanity, and ours.

"We understand all too well the heinousness and brutality of the crimes committed. We were there. We lived it," they wrote. "The defendant murdered our 8-year-old son, maimed our 7-year-old daughter, and stole part of our soul. We know that the government has its reasons for seeking the death penalty, but the continued pursuit of that punishment could bring years of appeals and prolong reliving the most painful day of our lives. We hope our two remaining children do not have to grow up with the lingering, painful reminder of what the defendant took from them, which years of appeals would undoubtedly bring."

Bombing survivor Marc Fucarile arrives to testify in the trial.

They're not alone. A recent Globe poll found that Bostonians overwhelmingly opposed the sentence, with just 15 percent of city residents wishing to see Tsarnaev executed, while 60 percent of Americans told CBS News that they wanted the death penalty. A recent New York Times story found ambivalence -- though little sympathy for the perpetrator -- on the streets of Boston as well.

"They ought to demonstrate a little humanity," former Bostonian Neil Maher, 66, told the paper. "Killing a teenager’s not going to do anything. I think it’s just a kind of visceral revenge. I think that in three years, the people of Boston and the people on the jury will feel bad about this decision."

Most Murders In The U.S. Are Committed By People Under 25

"And virtually every murder committed by someone under age 25 was not committed by someone who was emotionally healthy, or had reached their full adult potential," according to Robert Dunham, executive director of the nonprofit Death Penalty Information Center, which provides information and analysis on the death penalty to the media and public.

Dunham told MTV News that it's for that reason that it's not at all unusual to see the death penalty invoked for youthful killers. "We already know that if you're young, you are less morally and emotionally developed," he said. "But add in a youthful defendant in Tsarnaev, who depended on his older brother for his psychological well-being, evidence that his father and [allegedly] mother were mentally ill and unavailable."

In addition, Dunham said evidence in court cited his mother's and brother's radicalization, and you have a perfect storm of negative influences on an impressionable, not-fully-formed young mind.

Older brother Tamerlan.

Here's another thing to consider: Dzhokar never had a chance. Dunham explained that because the jury in the case was "death qualified" -- meaning it was composed of people who either are not opposed to the death penalty or don't think it has to be used in every capital murder case -- the jury was not really one of his peers.

"It's only people who say they are willing to cast the first stone," he said. "So many people in Boston said they were not willing to do that that you were left with a jury pool that couldn't possibly represent the conscience of the community. If he was tried in front of a typical Massachusetts jury, chances are he wouldn't get death."

Can The Boston Bomber Even Fully Comprehend What He's Done?

You're likely to find people who say that no matter what we know about adolescent brains, the gravity of Tsarnaev's crime suggests a depravity that clearly warrants the death penalty. Support for execution, it's worth noting, has fallen to new 40-year lows, according to a recent Pew poll.

It's also hard to know if Tsarnaev -- who kept a mostly stony appearance throughout the trial, only showing emotion when his aunt testified on his behalf -- can fully comprehend his sentence.

"There's a difference between knowing and appreciating something," Farahany said. "It's hard to show when a person is able to know something without coming to fully appreciate what the meaning is. Part of maturity is coming to appreciate things more and not just hearing them, but internalizing and understanding the unintended consequences before them."

Most 19-year-olds haven't seriously contemplated life, not to mention death, she added. "I can't make a judgement on whether it's [the death sentence] fair," Dunham said. "But I would say it's certainly less fair to impose it on someone who is impressionable and vulnerable than someone who isn't."