BOSTON >> Lawyers for Dzhokhar Tsarnaev, the surviving Boston Marathon suspect, are again asking a federal judge to delay his trial until September.

In a motion filed on Tuesday, Tsarnaev’s lawyers argued that the trial, currently scheduled to start with jury selection on Jan. 5, would begin faster than "99 of the 119 federal capital trials to get underway since 2004."

Tsarnaev, 21, has pleaded not guilty to 30 federal charges, including using a weapon of mass destruction, and faces the possibility of the death penalty if convicted. He was indicted 18 months ago.

Three people died and more than 260 were injured when two pressure cooker bombs went off at the finish line of the marathon on April 15, 2013.

Defense attorneys argue that a September 2015 trial date — or any additional delay the judge seeks to grant — would be more realistic and fair, given the "extraordinary complexity and international dimensions" of the case.

Judge George O’Toole, this past September, denied a similar request by Tsarnaev’s lawyers to delay the trial, as well as a related request to move the trial out of Boston.

But defense lawyers, in their Tuesday motion, argued that prosecutors continue to submit volumes of additional material as the trial approaches. Among them: a witness list naming more than 700 potential law enforcement and civilian witnesses and an exhibit list with 1,238 exhibits. Those and other documents were filed under seal last week.

The defense lawyers also express concern about its own investigation, which has required securing documents and witnesses from Chechnya, Dagestan, and Central Asia, according to the motion.

Earlier this week, Tsarnaev’s lawyers filed arguments again seeking to have his trial moved out of state, drawing parallels between media coverage of the case and that of the 1997 trial of Oklahoma City bomber Timothy McVeigh, which was moved to Denver.

Tsarnaev’s older brother, Tamerlan Tsarnaev, died in a shootout with police in the days after the bombing.