In what is being interpreted as a potential major breakthrough, police hunting the Washington sniper have arrested two men in connection with their investigation. They were seized as they slept in a car at a roadside stop in Frederick County in Maryland, not far from the U.S. capital. One is believed to be John Allen Muhammed, also known as John Allen Williams, whom police described as armed and dangerous. He was said to be travelling with his stepson, John Le Malvo, a seventeen-year-old Jamaican national. Authorities have said he may have information relevant to the Washington attacks, which have claimed ten lives.