Lawyers for Boston Marathon bomber Dzhokhar Tsarnaev have two weeks to file extra paperwork as part of their legal challenge to his conviction and death sentence in the devastating blasts, records show.

The US Court of Appeals for the First Circuit on Tuesday granted a motion from Tsarnaev’s taxpayer-funded legal team to file a supplemental brief, in addition to the approximately 500-page appellate brief his lawyers filed in December.

“Defendant’s Motion for Leave to File a Supplemental Opening Brief is allowed,” a Tuesday order filed with the court in Boston said. “The supplemental brief shall be limited to 10 pages and shall be filed within 14 days following the issuance of this order.”


The document said that a second motion from Tsarnaev for “Partial Reconsideration of Disclosure of Government Ex Parte Transcripts Concerning Discovery Matters is denied without prejudice to defendant re-raising the issue, if necessary, within 30 days after the appeal is fully briefed.”

Tsarnaev’s lawyers said in their December brief that the case was tainted when the presiding judge refused to change the trial venue and allowed jurors to serve who appeared to have lied during the selection process, among other issues.

Tsarnaev, 25, was convicted during an often-wrenching trial in federal court in Boston in 2015 and sentenced to death for his involvement in the 2013 bombings. He’s currently incarcerated at a federal supermax prison in Colorado.

His lawyers at trial admitted his role in the attack, which killed three people and wounded more than 260 others, but attempted to portray his older brother and co-assailant, Tamerlan, who died in a confrontation with police days after the blasts, as the dominant leader of the plot.

The brothers also killed an MIT police officer while they were on the run.

Tsarnaev’s lawyers wrote in their December brief that the trial judge committed a “grave error” by barring the defense from telling jurors that Tamerlan Tsarnaev was linked to a 2011 Waltham triple murder before enlisting Dzhokhar Tsarnaev into his plan to bomb the race.


Travis Andersen can be reached at travis.andersen@globe.com. Follow him on Twitter @TAGlobe.