Could you sentence a 21-year-old to death? 12 ordinary Americans just did.

Surely there is no greater or more weighty decision a person could face.

Could you sentence a 21-year-old to death? 12 ordinary Americans just did.

This is the question that 12 ordinary people randomly selected to form the jury charged with deciding whether Dzhokhar Tsarnaev would live or die asked themselves over two days of delicate deliberation.

Their verdict? Execution.

And it is a decision that will likely haunt these ordinary members of the community for the rest of their lives.

Last month, the now 21-year-old Boston Marathon bomber was found guilty of 30 offences, 17 of which carry the death penalty. Tsarnaev was just a teenager when he and his brother planted the two bombs that killed three people and injured hundreds. And now he will pay the ultimate price for his crimes.

When the jury looked at the baby-faced killer – a young man who bizarrely became a pin up for deluded teenage girls all over the world – they might have been reminded of their younger brother, their cousin, their son. It’s a face you want to forgive; there’s a youth and innocence that just doesn’t seem to gel with the horrible crimes Tsarneav has been convicted of.

But when the jury looked into the body of the courtroom, they also saw Tsarnaeav’s surviving victims. Some carry permanent physical scars of the attack on April 15, 2013. Some carry less visible but equally painful emotional or psychological scarring.

Three of those victims were not in the courtroom at all. Instead, they were represented by the family members who had to bury them after their lives were cruelly stolen by the Tsarneav brothers.

The youngest victim, eight-year-old Martin Richard, died in his mother’s arms near the marathon’s finishing line.

His father, Bill, told the jury how he left his son’s side as he lay dying in the street to save his injured seven-year-old daughter, whose leg was torn off by the explosion.

“I saw a little boy who had his body severely damaged by an explosion and I just knew from what I saw that there was no chance,” Mr Richard said.

“I knew in my head that I needed to act quickly or we might not only lose Martin, but we might also lose Jane too.”

In addition to killing Martin, the bombs killed Krystle Campbell, 29, and 23-year-old Lingzi Lu.

Another 264 people were treated in hospital. Some lost limbs, some needed bits of embedded shrapnel removed from their bodies. Others had hearing problems as a result of the blasts.

Three days after the bombs, the Tsaranevs shot dead 26-year-old police officer Sean Collier in order to steal his gun. Hours later, Dzhokhar’s older brother and fellow bomber, Tarmerlan, died after being shot by police and run over by Dzhokhar as he fled the scene.

Dzhokhar Tsaranev probably never expected to be facing capital punishment for his horrendous crimes.

Massachusetts state law does not allow for the death penalty but once the case was referred to the federal court, capital punishment became an option for the jury of decision makers.

Prosecutors literally called for his head, despite the pleas of Bill and Denise Richard, who experienced the devastating loss of one child and the permanent disablement of another at the hands of Tsarnaev.

They asked the prosecution to spare the life of the man who “stole part of (their) soul”, in exchange for a life sentence with no right of appeal, to put an end to the painful legal process for their young family.

But in dramatic closing arguments on Wednesday, prosecutor Steve Mellin said Martin’s parents’ suffering required a different penalty. He urged the jury to end Tsarnaev’s life, just like he ended that of his victims.

“The defendant deserves the death penalty not because he’s inhuman but because he’s inhumane,” Mr Mellin told them.

Defence lawyer Judy Clarke encouraged the jurors to move away from the government’s “eye for an eye” mentality and order life imprisonment for Tsarnaev instead.

“Even if you believe that is who Dzhokhar is, that is not who we are,” she said. “The law allows you to choose justice and mercy. We ask you to choose life.”

Having the huge decision of whether to end someone’s life hanging over your head is a situation ordinary Australians would never be in – even if our country did permit the death penalty as punishment for horrific crimes.

Because, here, judges are the ones that hand out sentences, juries are only ever involved in deciding guilt or otherwise. Those judges use their years of experience, combined with their knowledge of the law, to weigh up each sentencing consideration – including retribution, just punishment and rehabilitation – in order to reach their decision.

Judges, who deal with the horrible realities of all kinds of terrible crimes on a daily basis, are required to put aside their emotions and stick to the cold, hard law.

That is something that would be extremely difficult, if not impossible, to do for these jurors, who sobbed as they listened to graphic details of how the bombing victims bled to death in the street as a result of their injuries.

The weight of responsibility on the shoulders of the 12 ordinary Americans who were forced to choose whether a young man – a young man who did horrific things, but a young man nonetheless – should live or die, is unimaginable.

Surely there is no greater or more weighty decision a person could face.

I, for one, certainly don’t envy them. They have taken the decision to kill this young man, and they will live their own lives knowing that forever more. Wondering, always wondering, if it was the right and just decision.

For more on the Boston Marathon bombings, try these articles:

Breaking: Boston marathon bomber found guilty.

He was a Boston bombings survivor. She was the nurse who cared for him.

Boston: ‘I was on the block between the two explosions.’

Everyone is asking why Boston? This is why.