Prosecutors close case against Boston bomber with bloody video of day

In this courtroom sketch, Assistant U.S. Attorney Aloke Chakravarty is depicted pointing to defendant Dzhokhar Tsarnaev. Photo / AP

Prosecutors brought their case against Dzhokhar Tsarnaev, the only surviving suspect of the Boston Marathon bombing, to a dramatic close yesterday by filling the courtroom with the screams of the victims.

Jurors were shown video of the moment a pressure cooker bomb ripped through the crowds at the marathon finish line and heard the jihadist chants alleged to have motivated Tsarnaev to carry out the attack.

Footage showed the bloodspattered pavements and grievous wounds caused by the two home-made explosives, which killed three people and led to 17 amputations and hundreds of injuries.

Government lawyers asked the jury to remember those scenes of horror as they began deliberations to decide whether Tsarnaev is guilty of terrorist charges that could lead to the death penalty.

"Now is the time finally to hold him accountable," said prosecutor Aloke Chakravarty. He described the 21-year-old Tsarnaev and his older brother Tamerlan, who died in a shootout with police after the bombing, as hardened terrorists who wanted to kill civilians "to punish America" for its wars in the Muslim world.

"That day they felt they were soldiers. They were the mujahideen and they were bringing their battle to Boston."

Mr Chakravarty's voice quavered and he pointed at Tsarnaev as he showed pictures of each victim.

Tsarnaev, who was 19 at the time of the bombing, wore a grey shirt and dark suit and showed little reaction. His lawyers have already admitted his role in the worst terrorist attack on the American homeland since September 11 and they are not expected to dispute the facts laid out by the prosecution in their own closing argument.

Instead they will argue Tsarnaev was in thrall to his older brother, who they say masterminded the attack and recruited him into the plot.

The prosecution countered that Tsarnaev was engrossed in jihad in his own right and described how his computer and iPod were full of downloaded terrorist materials.

"He would put on his headphones and lose himself in the chants, lectures and music of jihad," said Mr Chakravarty.

Prosecutors reminded the jury that in the final moments before he was captured by police, Tsarnaev scrawled messages justifying the attack into the hull of a boat where he was hiding.

The note, obscured in places by his own blood, read in part: "Know you are fighting men who look into the barrel of your gun and see heaven, now how can you compete with that."

During a nearly hour-long closing statement, prosecutors reminded jurors of the April 15, 2013 bombing, but also how a five-day manhunt to capture the bombers ended in a shootout in a suburban street.

In one of the most chilling moments of the hearing, prosecutors showed a photograph of Tsarnaev in the moments before the bombs went off, a pale figure looming behind the three young children of the Richard family as they watched the marathon runners go by.

Tsarnaev allegedly held that position for four minutes after setting down his bomb inside a rucksack. The explosion that followed killed 8-year-old Martin Richard and tore the leg off his younger sister Jane.

"It was a heavy bag, the decision must have weighed on him," said Mr Chakravarty. "But these children weren't innocent to him. They were Americans."

If the jury convicts Tsarnaev of any of the possible death penalty offences, they will be called back for a second phase of the trial to determine if he should be executed.