Authorities on Monday swarmed communities outside of Philadelphia as they searched for a 35-year-old Pennsylvania man suspected of killing six people, according to reports.

Investigators believe Bradley William Stone of Pennsburg was involved in the incidents at three Montgomery County locations.

Stone’s name was released by the Montgomery County District Attorney’s Office on Monday afternoon, after SWAT teams were spotted in Souderton and Pennsburg earlier in the day.

“All of the victims have a familial relationship to Stone,” the office said in a statement.

According to the Associated Press:

On Monday afternoon, police converged on a home in Pennsburg, about 30 miles northwest of Philadelphia, and used a megaphone to try to compel an end to their daylong pursuit of Stone.
“Bradley, this is the police department!” an officer yelled. “Come to the front door with your hands up. You’re under arrest.”

The AP reports that the shootings happened in the neighboring towns of Harleysville, Lansdale and Souderton.

Authorities said Stone, who sometimes uses a cane or walker and might be wearing sand- or green-colored military fatigues, should be considered “armed and dangerous.” They asked that residents stay indoors as the search continued, and keep their doors locked.

“Anyone with information about Stone’s whereabouts is asked to call 9-1-1 immediately,” the statement said. “Do not approach him.”

[This post has been updated.]