RICHMOND, Va. — A federal appeals court has asked to hear additional arguments regarding the conviction of a former Russian military officer sentenced to life in prison for leading a Taliban attack on U.S. forces.

The 4th U.S. Circuit Court of Appeals in Richmond scheduled new arguments for December in the case of Irek Hamidullin, who says he should be treated as a prisoner of war and shielded from prosecution.

Hamidullin was convicted of leading a 2009 attack on U.S. forces in Afghanistan.

Hamidullin’s attorneys argued he shouldn’t have faced trial because he is a lawful combatant.

But prosecutors said fighters aligned with the Taliban don’t qualify for lawful-combatant status.

One of the judges who heard arguments in December, Andre Davis, has since announced he is stepping down to serve as Baltimore’s solicitor.