One suspect in Marathon bombing apprehended, another remains at large, according to source

WATERTOWN — One suspect in Monday’s Boston Marathon bombings has been apprehended, according to an official with knowledge of the investigation. Another appears to remain on the loose in Watertown after a firefight with police. A 20-block perimeter was established as authorities searched for him. -  One suspect in Marathon bombing apprehended, another remains at large, according to source
Live blog: Bombings at the Boston Marathon - Boston