Lawyers representing Boston Marathon bombing suspect Dzhokhar Tsarnaev petitioned a federal judge to postpone his upcoming trial for nine months.

Tsarnaev and his now deceased brother, Tamerlan Tsarnav, are accused of planting two bombs at the finish line of the Boston Marathon on April 15, 2013, killing three people and injuring 264 others. In addition, prosecutors say that the Chechen brothers fatally shot a Massachusetts Institute of Technology police officer three days later. Tamerlan, 26, was then killed in a gun battle with police on April 18.

The 21-year-old suspected terrorist has pleaded not guilty to 30 charges connected to the explosions and could face the death penalty if convicted. The defense, however, argues that Tamerlan was the mastermind behind the attack.

On Monday, Tsarnaev's legal team said that they need more time for preparation and asked a judge to delay the trial, which is set to begin Jan. 5, until September. They also argued that prosecutors have withheld evidence that would help prove that the accused terrorist was being influenced by Tamerlan.

"The brothers' alleged 'radicalization' is a more complex story over a longer period of time that can only be understood by painstaking analysis of activity across multiple electronic devices that the government has seized," the defense wrote in a filing, according to NBC News.

Prosecutors, on the other hand, previously said they have handed over all required documentation.

In response, defense lawyers wrote in the filing that "Only adequate preparation makes a fair trial possible. But we face a situation where Mr. Tsarnaev is being afforded substantially less time to prepare than the vast majority of defendants in federal capital cases," reports the Associated Press.

They added that they recently received over 19,000 pages of documents along with spreadsheets and audio files earlier this month, adding to the massive volume of evidence that they need to review.

The defense also wants more time to review information regarding Stephen Silva, the man who recently confessed to having once possessed the gun that prosecutors said the bombing suspects used to kill the police officer at MIT.

Also on Monday, Tsarnaev's lawyers filed a document with the court in support of their motion to move the trial out of Massachusetts due to the intense media coverage surrounding the case.

It was not immediately clear when the judge would rule on the motions to delay or move the trial.