Boston bombings suspect Dzhokhar Tsarnaev wants trial moved to D.C.
This undated image released by the FBI shows Marathon bombing suspect Dzhokhar Tsarnaev (AFP)

The prime suspect in the Boston Marathon attacks has asked a US court to move his trial to Washington, DC claiming he will not be tried fairly in the northeastern city.

The April 15, 2013 attacks, which killed three people and injured 264 others, were allegedly planned and carried out by ethnic Chechen brothers Tamerlan and Dzhokhar Tsarnaev.

Tamerlan was shot dead by police on April 19, 2013, after killing an officer.

Dzhokhar is due to stand trial in Boston in November, accused of 30 federal charges and could face the death penalty if convicted.

But in a 10-page court document filed late Wednesday, his lawyers asked that his trial be moved to Washington DC to assure him the fairest possible trial.

A survey revealed "an overwhelming presumption of guilt" in Boston, "prejudgment as to the penalty that should be imposed" and "an extraordinarily high number" of potential jurors who attended the 2013 marathon or who know someone who did, it said.

"Our preliminary review of the information collected leads us to conclude that prejudice must be presumed in the District of Massachusetts," the document said.

"Accordingly, we seek a change of venue."

The lawyers presented findings from surveys in Boston, the western district of Massachusetts, Manhattan and Washington DC, presenting the federal capital as the "least prejudicial."

They pointed out that publicity, local impact and "galvanizing community reaction" changed the venue in the trial of the Oklahoma City bombing, arguing that in this case the community impact was even greater.

Last month, lawyers for Tsarnaev also asked that capital punishment be ruled out for their client -- a request prosecutors opposed in a separate document.

Federal death penalty cases are relatively rare in the United States, and are often reserved for the most heinous and notorious crimes.

Oklahoma City bomber Timothy McVeigh was executed in 2001, following the 1995 bombing of a federal office building that killed 168 people and injured more than 600.