WATERTOWN, Mass. — Joseph Gagnepain, 32, who grew up in New Vineyard and whose parents live in Jay, said he spent a sleepless night inside the door of his Lincoln Street home, holding a sword in his hand.

Gagnepain said he had left to go to a convenience store about 11:30 Thursday night when he saw a group of more than 100 police cruisers go by, taking more than a minute to pass at about 45 mph.

Gagnepain said he was only three or four blocks from the shoot-out between the bombing suspect and police, but he didn’t distinguish the sounds of gunfire from the continuous din of the sirens and barking dogs in the neighborhood.

When Gagnepain saw the size of the police presence, he said, he returned home, where he and his three roommates tuned in to a police scanner to monitor the situation. They were concerned about the house’s three doors, which had glass panes.

“Anyone could come in,” he said. “We had a person posted at each door, watching out the window.”

Gagnepain, who said he has trained in martial arts three or four days a week for the past 12 years, acknowledged that the swords were not an ideal defense against a potential intruder with a gun.

“But I don’t have a firearm in the house,” he said. “We each had a sword at a doorway, which feels ridiculous. It’s scary.”

Friday morning, Gagnepain said, a group of about 50 armed SWAT team members wearing helmets, body armor and communication pieces on their ears conducted a door-to-door search on the street.

A group of five searched his house, including the basement, which Gagnepain said was a particular concern because it had an exterior door and could have been an entry point for the bombing suspect.

Both Murphy and Gagnepain said the officers were professional and calm, and that they welcomed their presence.