As investigators look into the Boston Marathon bombings, one crucial question is whether the suspects, brothers Tamerlan and Dzhokhar Tsarnaev, acted alone or had help. The clues might be found in the bombs used.
From what is now known, it appears the brothers assembled a whole arsenal of explosives. Watertown Police Chief Edward Deveau told CNN last weekend that the suspects had at least six bombs, including the two used in the attack and one thrown at police during a shootout.
Footage from surveillance cameras along the Boston Marathon route gave the FBI early clues about the bombing suspects. And prosecutors say they'll use some of those images to try to prove their criminal case against 19-year-old Dzhokhar Tsarnaev. But the proliferation of cameras in America's big cities is raising some tricky questions about the balance between security and privacy.
It was pictures of two brothers taken by a camera outside the Lord & Taylor department store that provided the first glimpse of the men who allegedly bombed the Boston Marathon.
Though they told him he wouldn't be hurt, the man who was allegedly forced by the suspects in the Boston Marathon bombings to hand over his SUV and go with them says he was convinced the gunmen would "kill me later."
Local officials have defended the decision to essentially lock down the city of Boston on Friday while law enforcement searched for a suspect in the Boston Marathon bombing.
Residents were told to remain indoors during the hunt for Dzhokhar Tsarnaev, who survived an early morning shootout with police in the suburb of Watertown during which his brother, Tamerlan, was killed.
Massachusetts Gov. Deval Patrick announced the decision to lock down Watertown and the surrounding areas, including Boston, at a dawn news conference Friday.