Attorney General Eric Holder to seek death penalty for accused Boston bomber

The United States is to seek the death penalty for accused Boston bomber Dzhokhar Tsarnaev if he is convicted of involvement in the deadly attack, Attorney General Eric Holder said Thursday.

"The nature of the conduct at issue and the resultant harm compel this decision," Holder said in a statement on the prosecution of the 20-year-old, a US citizen from a Chechen Muslim family.

Three people were killed and around 260 wounded on April 15 last year when two bombs made of explosives-packed pressure cookers exploded near the finish line of the Boston marathon.

Tsarnaev, then 19, and his 26-year-old brother Tamerlan Tsarnaev were cornered by police after a four-day manhunt. Tamerlan died after an exchange of fire with police and Dzhokhar was wounded.

The shaggy-haired onetime student has pleaded not guilty to 30 federal charges related to the bombings, including 17 serious charges that can carry sentences of death or of life in prison.

These charges include using a weapon of mass destruction resulting in death, as well as conspiracy and bombing of a place of public use resulting in death, and carjacking.

Tsarnaev is also charged in connection with the shooting death of a campus police officer at the Massachusetts Institute of Technology during the brothers' wild overnight getaway attempt.

The brothers are said to have built the bombs with help from an online Al-Qaeda magazine, but they are not accused of having received help from any organized foreign terror group.