FREDERICK, Maryland (CNN) -- A Bushmaster .223-caliber rifle was recovered from the vehicle impounded during the overnight arrest of two suspects in the Washington-area sniper case, a law enforcement source told CNN Thursday.
John Allen Muhammad, 41, also known as John Allen Williams, a Gulf War veteran, and his 17-year-old stepson John Lee Malvo, a Jamaican citizen, are to be arraigned Thursday afternoon in U.S. District Court in Baltimore, Maryland.
All the sniper victims -- 10 dead, three wounded since October 2 -- were hit by a single .223-caliber shot. Washington radio station WTOP reported that a rifle, a scope and a tripod had been recovered from the suspects' vehicle.
A source also told CNN that the car -- a blue 1990 Chevrolet Caprice -- had been modified with a hole bored in the trunk, which could allow someone to shoot from inside the vehicle. The rifle was found behind a seat.