One of the first things David Henneberry did after authorities lifted a lockdown during the April 19, 2013, search for Boston Marathon bombing suspect Dzhokhar Tsarnaev was to go check on his boat.
What he found there brought the dragnet to a bloody, frantic end.
Earlier that day, Tsarnaev had sped away from a pre-dawn shootout with police that left his older brother, Tamerlan, dead. That showdown, four days after twin blasts had rocked the marathon’s finish line, happened less than a mile from Henneberry’s home in Watertown, Massachusetts.
Police in SWAT gear had swarmed into the small suburb, searching houses and…