The attorney of the D.C. sniper who pleaded guilty to the 2002 attacks is challenging his life sentences in a Montgomery County court Thursday.
Lee Boyd Malvo claims his six life-without-parole sentences in the county are illegal because the Supreme Court says such sentences for juveniles are unconstitutional except in certain cases.
Malvo was 17 when he killed 10 people and hurt three others.
Last month, a judge in Virginia said the 32-year-old should be sentenced again because the life sentences imposed when he was a teenager are unconstitutional.