The Montgomery County Police Department said 66-year-old Mary Olson, 70-year-old Danny Murphy and 54-year-old Craig Shotwell were shot and killed by 41-year-old Christopher Snyder at Olson's home at 222002 Brown Farm Way in Brookeville, Maryland at about 3:45 p.m.
After the fatal shootings, Snyder reportedly barricaded himself in his home in a police standoff that lasted more than six hours. Snyder went to the home and shot and killed the three others, authorities say.
Snyder was on the phone with police negotiators when police breached his home, Manger said.
Residents were told to shelter in place, and police set up a perimeter around the home. Negotiators called him to try to get him to surrender. One was Snyder's wife, police say.More news: Iran-Backed Hezbollah Gains Tighter Control Over Lebanon Through "Decisive" Election Victory
Police reportedly found "a number" of guns in the home, Manger said at the press conference.
Manger said that gunfire could be heard in the background of 911 calls that sent police to the scene. Snyder also mentioned he had explosives in his house during his talks with the negotiator and hence, the police continued to search his property late into the night. His wife told investigators that Snyder had held her captive in their home for the weekend prior, and that she took an opportunity to flee the home on Monday. The three weren't the only ones there at the time of the shooting, however.
According to reports, Snyder had a history of run-ins with police, and his address is listed as gun dealer Black Widow Enterprises, LLC.
Some lanes of New Hampshire and Georgia avenues were blocked.