(CNN) -- Three Pittsburgh, Pennsylvania, police officers were shot to death while responding to a 911 call of a domestic argument triggered by a urinating dog, according to a criminal complaint filed in the case.

Law enforcement from several jurisdictions respond to a shooting standoff at Pittsburgh home Saturday. more photos »

The officers were the first department fatalities since 1995, according to the department.

Police said following the shootings Saturday that Richard Poplawski, 22, would be charged with three counts of homicide, aggravated assault and other charges. Poplawski, who was shot in the leg during a four-hour standoff with police, was hospitalized at an undisclosed location, police said.

Details of the incident were included in the police complaint seeking an arrest warrant for Poplawski. The complaint says Margaret Poplawski called 911 about 7 a.m. Saturday to report that her son was "giving her a hard time." Watch officers respond at the scene »

She told police she awoke to discover that "the dog had urinated on the floor," and awakened her son "to confront him about it."

The two had an argument, and Margaret Poplawski told her son she was calling police to remove him from her home, according to the complaint. When officers Stephen Mayhle and Paul Sciullo III arrived, she opened the door and let them in.

"Mrs. Poplawski reported that as the officers entered approximately 10 feet into the residence, she heard gunshots, turned and saw her son about six feet away with a long rifle in his hands, at which point she fled downstairs after asking him, 'What the hell have you done?'" the complaint said.

Margaret Poplawski reported she stayed in the basement during the standoff, and heard her son yell, "Yeah, I've been shot," and "I'm standing down, come in and help me," according to the complaint.

Police Chief Nathan Harper identified the dead officers as Eric Kelly, Mayhle and Sciullo. Kelly was a 14-year veteran of the department; the other two had worked there for two years each. Watch prayers for fallen officers »

The chief said Sciullo was the first to approach the home, and was shot in the head as he entered the doorway. When Mayhle tried to help his fellow officer, he also was shot in the head. Kelly arrived at the scene and was shot before he could aid the other two officers, Harper said.

Harper said the suspect fired from a bedroom window, shooting at an armored vehicle carrying a SWAT team -- preventing those officers and medics from reaching the wounded policemen.

Two other officers, Timothy McManaway and Brian Jones, were injured. McManaway was shot in the hand and Jones, who was trying to secure the rear of the house, broke his leg trying to get over a fence, Harper said.

Rescue units from other jurisdictions also were met with gunfire, the chief said.

McManaway told police he responded to the scene after a report that officers were being fired upon, according to the complaint. As he arrived, he saw that Kelly was "lying supine" by his personal SUV, as Kelly had just completed his shift and apparently was on his way home when he responded to help the other officers.

Kelly raised his arm for help, and McManaway said he ran to Kelly, who was wounded and said he could not breathe. As he was trying to help Kelly, shots rang out from the home, injuring his hand, he said, according to the complaint.

McManaway returned fire, and told authorities he pulled Kelly behind the SUV, where the two remained until SWAT officers arrived. Kelly was taken to a local hospital, where he died of his injuries.

Margaret Poplawski told police her son had enlisted in the Marine Corps a few years ago, but was discharged for assaulting his drill sergeant in basic training, according to the complaint. Since his discharge, she told police, he had been "stockpiling guns and ammunition, buying and selling the weapons online, because he believed that as a result of the economic collapse, the police were no longer able to protect society. Mrs. Poplawski reported that her son only liked police when they were not curtailing his constitutional rights, which he was determined to protect," the complaint said.

Autopsies showed that Kelly died of gunshot wounds to the trunk and lower extremities, Sciullo died from gunshot wounds to the head and trunk, and Mayhle was shot in the head, the complaint said.

"We have never had to lose three officers in the line of duty on one call," Harper, the police chief, said. "They have paid the ultimate sacrifice."

Authorities believe Poplawski, wearing a bullet-proof vest, aimed more than 100 rounds at police, using an AK-47, Harper said Saturday.

Harper said some neighbors were evacuated during the standoff.

Police had responded to calls from the home two or three times previously, Harper said.

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