Lawyers for convicted "Beltway sniper" Lee Boyd Malvo are appealing a federal judge's rejection of his claim that his life sentence is unconstitutional, according to court documents.
Malvo's attorneys filed a notice of appeal on Wednesday, claiming that a 2012 Supreme Court decision that prohibits mandatory sentences of life without parole for juveniles should apply to his case. Malvo was 17 at the time of the shootings.
A federal judge in Norfolk, Virginia, rejected the claim last month.
Malvo and his adult accomplice John Allen Muhammad terrorized Washington-area residents in a three-week killing spree in October 2002. Ten people were killed and three seriously injured in Washington, Virginia and Maryland.
They were convicted of the killings in 2003 and Malvo was sentenced to life in prison. Muhammad, a Gulf War veteran, was executed by lethal injection in Virginia in 2009.
Calls to Malvo's attorneys Craig Cooley and William Brennan were not immediately returned.
(Reporting by John Clarke in Annapolis, Maryland; Editing by Ian Simpson and Eric Beech)