Two people were found dead this morning inside a home in South Strabane after an all-night standoff with police.
A third person was injured in the incident, which began about midnight.
Police said an estranged husband went to his wife's home and killed her and shot her boyfriend. The gunman killed himself after an hours-long standoff with officers, police said.
Washington County Coroner Tim Warco identified the man as Harold McCutcheon Jr., 56. He died of a self-inflicted gunshot wound to the head.
A press release from the coroner said tactical officers found Mr. McCutcheon in a bedroom of the home after he held police at bay for hours.
His wife, Terry McCutcheon, 52, also was found dead in a bedroom of a gunshot wound to the chest, Mr. Warco said. Her death was ruled a homicide.
Ms. McCutcheon's male friend also was wounded but escaped from the home and was taken to a Pittsburgh hospital, Mr. Warco said.
Officers went to Arrowhead Drive at 11:49 p.m. for a report that someone had been shot.
"A 911 caller reported that a man walked into their residence with an apparent gunshot wound, and told the caller that he had been shot at another residence," Sgt. Drew Hilk wrote in a press release.
Officers contacted the Washington Area SWAT team after hearing more gunshots, the sergeant said.
Just after 6 a.m. tactical officers entered a home on that street and found two people dead of apparent gunshot wounds, police said.
Police did not fire any shots, South Strabane police Sgt. Mike Manfredi said.
"But when police were present shots were fired," he said.
Lou Haddad, who lives in a townhouse across the street with his partner and a pug, said he first heard a "very loud gunshot that was very close" about midnight.
By 2:30, he saw tactical officers outside and heard one announce, "It's the police. Come out with your hands up."
A short time later, he and neighbors were evacuated and waited hours in the State Farm insurance parking lot inside a Meadows Casino shuttle bus.
At one point, two bullets went through Mr. Haddad's front door.
"I thought it was a dream," he said. "We don't experience this in South Strabane."
Neighbors were allowed back in their homes about 7:30 a.m. This residential street of attractive townhouses and well-manicured lawns -- called Strabane Manor, neighbors said -- was still busy with police activity late morning.
The coroner's office was called to the scene shortly after 10 a.m.
Pittsburgh Post-Gazette reporter Molly Born and The Associated Press contributed.