paralysis in the city of boston. >> what was that? was that guns? >> but it would soon end in watertown. [ gunfire. >> i just heard what sounded like multiple assault rifle shots. >> it sounded like police emptying their weapons, rapidly fired and then all of a sudden it stopped. >> there was a lot of commotion over in this area. we just saw more polices vehicles with their lights going. >> they have the suspect. they believe it is the a suspect. they know exactly where he is. they have cordoned off a section of watertown. >> clear out, okay? >> by 8:15 p.m., law enforcement officials say a person believed to be dzhokhar tsarnaev is cornered, hiding on a boat in a backyard. finally, at 8:46 p.m., he's in custody and taken to the hospital with gunshot wounds. minutes before 9:00 p.m., this