<P> A 20 - block area of Watertown was cordoned off and residents were told not to leave their homes or answer the door as officers in tactical gear scoured the area . Helicopters circled the area and SWAT teams in armored vehicles moved through in formation, with officers going door - to - door . On the scene were the FBI, the Bureau of Alcohol, Tobacco, Firearms and Explosives, the Department of Homeland Security, the National Guard, the Boston and Watertown Police departments and the Massachusetts State Police . The show of force was the first major field test of the interagency task forces created in the wake of the September 11 attacks . </P> <P> The entire public transit network, as well as most Boston taxi service, was suspended, as was Amtrak service to and from Boston . Logan International Airport remained open under heightened security . Universities, schools, many businesses, and other facilities were closed as thousands of law enforcement personnel participated in an unprecedented door - to - door manhunt in Watertown, as well as following up other leads, including at the house the brothers shared in Cambridge . Seven improvised explosive devices were recovered by bomb squads . </P> <P> The brothers' father, speaking from his home in Makhachkala, Dagestan, encouraged his son to: "Give up . Give up . You have a bright future ahead of you . Come home to Russia ." He continued, "If they killed him, then all hell would break loose ." On television, Dzhokhar's uncle from Montgomery Village, Maryland, pleaded with him to turn himself in . </P> <P> On the evening of April 19, two hours after the shelter - in - place order had been lifted, a Watertown resident outside the search area noticed that the tarp of his parked boat was loose, then saw a body lying inside in a pool of blood . Authorities surrounded the boat and verified movement through a thermal imaging device in a police helicopter . When the person inside started poking at the tarp, police shot at the boat . </P>

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