Boston bombing trial begins

The trial of the man accused of bombing the Boston Marathon two years ago has begun, with his defence lawyer telling the jury he committed the crime.

"It was him," the lawyer said as she prepared to defend Dzhokhar Tsarnaev's actions by saying he had been influenced by his older brother.

Mr Tsarnaev, 21, could face the death penalty and is charged with more than 30 counts relating to the bombings.

It was the deadliest terror attack on US soil since 9/11.

Three people, including an eight-year-old boy, were killed after two pressure cooker bombs packed with nails, ball bearings and other shrapnel detonated in April 2013. More than 260 people were injured, with many losing limbs.

In 2013, Mr Tsarnaev pleaded not guilty to all charges, including one related to the killing of a police officer in the days after the bombing.

The admission marks the beginning of the defence team's strategy, which is to place blame for the bombings on the defendant's older brother Tamerlan, who was killed by police.

"The evidence will not establish and we will not argue that Tamerlan put a gun to Dzhokhar's head or that he forced him to join in the plan," Ms Clark told the court, "but you will hear evidence about the kind of influence that his older brother had."

She said that her team would not attempt to "sidestep" Mr Tsarnaev's guilt in carrying out the "senseless, horribly misguided acts carried out by two brothers".

Instead, she will argue that Tamerlan was the mastermind of the plot who coerced the younger sibling into being a submissive participant.

Ms Clark has helped a number of high-profile clients avoid execution. They include the so-called Unabomber, Ted Kaczynski and the man responsible for killing six people and severely wounding former congresswoman Gabrielle Giffords, Jared Loughner.

The entire trial is expected to last three to four months.