Scenes from Boston bombing manhunt
A look at the past 24 hours.
STRThis photo shot through a window screen provided by Samantha England, shows police in tactical gear outside England's home in Watertown, Mass. Friday, April 19, 2013. The two suspects in the Boston Marathon bombing killed an MIT police officer and hurled explosives at police in a car chase and gun battle overnight that left one of them dead and his brother on the loose, authorities said Friday as thousands of officers swarmed the streets in a manhunt that all but paralyzed the Boston area. (AP Photo/Samantha England)