Jonathan Sheldon told a federal appeals court Tuesday that the failure of Muhammad's trial attorneys to tell a judge about their client's mental health issues violated his constitutional right to effective counsel.

A lawyer for the state of Virginia argued that Muhammad's competency was never an issue in his trial for one of the 10 murders committed by Muhammad and teenage accomplice Lee Boyd Malvo. Muhammad was sentenced to death, and Malvo is serving a life term for the 2002 Washington, D.C.-area shooting spree.

The federal appeals court in Richmond, Va., is expected to rule in several weeks.