US prosecutors seek death penalty for accused Boston bomber

Attorney general says the conduct and the resultant harm led to the decision against the 20-year-old accused of orchestrating deadly Boston marathon attack

A pair of homemade pressure-cooker bombs killed three people and wounded 264
A pair of homemade pressure-cooker bombs killed three people and wounded 264

Federal prosecutors in the compilation of evidence of accused Boston marathon bomber Dzhokhar Tsarnaev said they would seek the death penalty.

"Tsarnaev should be put to death if he is found guilty of planting devices that killed three people and wounded 264 at the Boston Marathon last year," the US government's chief prosecutor has said.

Attorney General Eric Holder said in a statement on Thursday that he was authorising trial prosecutors to seek the death penalty against Tsarnaev, who is charged with committing one of the worst attacks on US soil since the September 11, 2001, attacks.

"The nature of the conduct at issue and the resultant harm compel this decision," Holder said.

The 20-year-old is accused of helping orchestrate the April 15 blasts that killed three people and wounded more than 260 others.

Seventeen of the 30 federal charges levelled against Tsarnaev carried the possibility of the death penalty, including using a weapon of mass destruction to kill.

Holder had faced a Friday deadline for deciding whether to seek the death penalty as part of Tsarnaev's upcoming trial.

Prosecutors say that Tsarnaev, 20, and his 26-year-old brother Tamerlan, planted a pair of homemade pressure-cooker bombs at the race's crowded finish line on April 15, 2013, killing three people and wounding 264.

Three nights later, the pair killed a university police officer and later, the elder Tsarnaev was shot dead by police during a getaway attempt while, the younger of the two brothers suffered wounds before escaping on foot.

He was later found hiding in a boat parked in the yard of a suburban Boston home. Authorities said he wrote about his motivation for the bombing on the inside of the boat.

The younger Tsarnaev has pleaded not guilty to criminal charges. A trial date has not been set.

US justice department officials said the nearly seven months since the attack was necessary to fully evaluate the circumstances of the case and to gather recommendations from prosecutors advising Holder.