ROCKVILLE, Md. (AP) - Washington-area sniper John Allen Muhammad was convicted of six more of the killings Tuesday after a trial in which he acted as his own attorney and the prosecution's star witness was his young protege and partner in crime, Lee Boyd Malvo.

Muhammad, 45, is already under a death sentence in Virginia for a killing there. The most he can get for the six Maryland slayings is life in prison without parole.

The jury took slightly more than four hours to convict him after a four-week trial. The trial marked the first time Malvo testified against the man prosecutors say was his mentor and manipulator.

During two days of testimony last week, Malvo, 21, gave the first inside account of the shootings and described Muhammad's elaborate plans for a reign of terror.

(Copyright 2006 by The Associated Press. All Rights Reserved.)

AP-NY-05-30-06 1432EDT