Defence Rests In Boston Marathon Bombing Trial

Lawyers for accused Boston Marathon bomber Dzhokhar Tsarnaev have rested their case.

The defence, which has acknowledged Tsarnaev's role in the attacks, called on just four witnesses in the hopes of convincing jurors that he was pressured by his older brother into carrying out the bombings.

FBI fingerprint examiner Elaina Graff testified on Tuesday that only Tamerlan Tsarnaev's fingerprints were found on two pieces of cardboard that came from one of the pressure-cooker bombs used at the marathon.

She said prints belonging to both brothers were found on another bomb recovered from the scene of a gun battle with police days after the attack.

The elder Tsarnaev was killed when his younger brother inadvertently ran him over with a hijacked car following the shoot-out.

The defence has attempted to pin the bulk of the blame for the bombings on the older brother in order to persuade the jury to spare Tsarnaev the death penalty.

They claim that Tsarnaev, then 19, fell under the influence of his 26-year-old radicalised brother.

Closing arguments are set to begin on 6 April, after which a jury will decide Tsarnaev's fate on 30 federal charges.

If convicted, a second phase of the trial will get under way, during which jurors will hear additional testimony before determining Tsarnaev's sentence.

The 21-year-old is accused of killing three people and injuring 264 others in the twin attacks near the Boston Marathon finish line on 15 April 2013.

He is also charged in the fatal shooting of an MIT police officer days after the bombings.

Prosecutors wrapped up their case on Monday after showing graphic autopsy photos of two of the three bombing victims, including the youngest, eight-year-old Martin Richard.

At least three jurors could be seen crying as the gruesome images were displayed in court.

Massachusetts' chief medical examiner testified that Martin suffered injuries to virtually every part of his body.