In Watertown, the Massachusetts State Police, FBI, and local police conducted a door-to-door search of homes on about 20 streets. They came up empty handed.
By 6 p.m., authorities said they believed the suspect was still in the region but they lifted the order to stay inside.
After being cooped up all day, David Henneberry wanted to check on his boat -- his favorite toy, his "baby" -- named Slip Away II. He had noticed from his house that its cover had come slightly off.
It had irked him for much of the day. The winds had been unusually strong that day. Henneberry figured the winds had loosened the cover.
He climbed three steps up a ladder and saw "a good amount of blood," Henneberry told CNN-affiliate WCVB.
"I said, 'Wow, did I cut myself last time?'"
"Then, I just look over there, and there is more blood," he told WCVB. "I looked back and forth a couple of times and my eyes went to the engine block and there was a body. ..."
"He was just laying there by the engine block and the floor. I couldn't see his face. I'm glad I didn't see his face," he said. "He didn't move."
Henneberry called 911.
Moments later, hundreds of authorities, ranging from FBI agents, SWAT team members and specialty tactical units, arrived at 67 Franklin Street. Gunfire and flash bangs, meant to stun people, echoed through the neighborhood.
A state police helicopter used a thermal imaging camera to determine that Dzhokhar was alive and moving. A robotic arm was used to remove part of the tarp and further reveal the suspect.
Eventually, he stood up and lifted his shirt for officers to show that he didn't have an explosive vest. "At that point," Deveau said, "we felt comfortable enough to send some officer tactical equipment to grab him and pull him away from the boat."
At 8:45 p.m., Boston police tweeted: "CAPTURED!!! The hunt is over. The search is done. The terror is over. And justice has won. Suspect in custody."
About that time, raucous cheers roared down Franklin Street. Federal agents with sub-machine guns, firefighters in protective gear, SWAT team members in full body armor, hundreds of them, raise their arms in victory and hooted in jubilant fashion.
Residents on the lawn of the Church of the Good Shepherd joined in the revelry. Every time a tactical team member emerged, neighbors applauded and shouted "Thank you!"
One policeman, about 6 foot, 4 inches and 250 pounds, had stood guard for much of the night with two comrades, a formidable barricade to keep reporters away. Amid the celebratory cheers, a reporter asked if the suspect had been captured.
A smile spread across his face. "Yes," he said.