Officials on Thursday identified the three police officers that were killed when they were ambushed while responding to a domestic call Wednesday in York County, Pennsylvania.

The fallen included Northern York County Regional Police Department’s Sgt. Cody Becker, Detective Mark Baker and Detective Isaiah Emenheiser, according to York County District Attorney Tim Barker.

Another Northern York County Regional Police detective and a York County Sheriff’s Office deputy were critically wounded, but remain stable at the hospital, Barker said.

The suspected gunman, identified as Matthew James Ruth, 24, was killed by police, officials said. He did not have any prior criminal convictions.

5 POLICE OFFICERS SHOT, 3 DEAD IN PENNSYLVANIA, FBI INVESTIGATING 

Barker said that the investigation began on Tuesday night, when Ruth’s ex-girlfriend’s mother reported seeing him on her property in camouflage, peering into the home with binoculars. Trail camera footage showed Ruth armed with an AR-15-style rifle, and his truck was left nearby. 

The ex-girlfriend also told police her pickup truck was set on fire in August, but she was not sure if Ruth was to blame, so she requested they not investigate.

Detectives returned to the empty home just after 2 p.m. Wednesday, and as they walked through the unlocked front door, the suspect launched an ambush, firing multiple suppressed rounds, according to Barker. Ruth was later killed in a final shootout near the road.

Inside the house, investigators later discovered shell casings from the initial ambush and, in the basement, the body of the ex-girlfriend’s mother’s black Labrador, which the suspect had shot and killed.

Authorities are continuing to investigate the motive, but Barker emphasized the root of the tragedy was domestic violence.

“All actions by law enforcement were justified. They weren’t only justified, they were necessary,” Barker said. “We are so thankful and appreciative to them, and especially our northern York County Regional detective who fired the last shot and who rendered aid. I can’t imagine the strength and the fortitude that it takes to immediately, after having seen and been engaged in that … immediately thinking of rendering critical aid.”

MULTIPLE OFFICERS INVOLVED IN PENNSYLVANIA SHOOTING AS GOVERNOR RUSHES TO YORK COUNTY SCENE 

“He saved many lives that day,” he added. “If the actor was not eliminated, and his threat and murderous rampage eliminated, who knows where this would have stopped.”

Prior to the shooting, Ruth was charged with stalking, trespassing, loitering and prowling at night in relation to the investigation, court documents show. 

The FBI, Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), and the Pennsylvania State Police are assisting local authorities. Attorney General Pam Bondi offered the full support of the federal government. 

The shooting, which took place about 115 miles west of Philadelphia in North Codorus Township, came just a few months after another York County officer was killed in the line of duty. 

Pennsylvania Gov. Josh Shapiro said during a news conference Wednesday he is continuing to pray for everyone involved. 

“This is an absolutely tragic and devastating day for your county and for the entire Commonwealth of Pennsylvania,” Shapiro said. “[We] grieve for the loss of life of the three precious souls who served this county, served this commonwealth and served this country. We continue to pray for the full recovery of those who are dealing with their wounds.” 

The Associated Press contributed to this report.