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.’’