BEDFORD — A nearly four-hour police standoff Sunday at a Boynton Street residence ended when a police robot found a man dead in his basement.

Police Chief John Bryfonski said police heard two gunshots when they responded to the residence, which a fire official said was 435 Boynton St., after receiving a call from a woman about a despondent and armed man in the house. After that, “due to safety concerns,” a state police tactical team of more than a dozen officers was called in, he said.

“Once we heard the gunshots, we created a safe perimeter and state police set up a tactical scene,” Bryfonski said.

That scene included blocking off a long stretch of Boynton Street between Plummer Road and Route 101 and evacuating homes that were “within range” of the gunman, Bryfonski said.

About 6 p.m. Sunday, a camera-equipped robotic rover was sent into the house and found the man in the basement. Bryfonski said his name was not being released Sunday night because police were still trying to notify next of kin. When police arrived, they found a woman, who “was obviously upset” and was the last person to have contact with the man, Bryfonski said.

“We never had contact with the subject,” he said.