Three police officers were fatally shot and two others wounded as they responded to a domestic dispute in Pittsburgh early Saturday morning.

Police Chief Nathan Harper said Richard Poplawski, 22, shot all three officers while his mother was taking refuge in the basement of their home, and that he surrendered after a nearly four-hour standoff with officers.

This latest killing spree came less than a day after a gunman murdered 13 people at an immigrant services center in Binghamton, N.Y., before killing himself, and three weeks after a 26-year-old parolee shot and killed four police officers in Oakland, Calif.

“We have never had to lose three officers in the line of duty in one call,” Chief Harper said at a news conference in the lobby of police headquarters in downtown Pittsburgh. The American flag and the Pittsburgh flag flew at half-staff just outside the building to honor the slain officers — Eric Kelly, a 14-year veteran of the force, and partners Paul Sciullo III and Stephen Mayhle, each of whom had been with the department just two years.

Pittsburgh Gunman Victim Photo

“No matter how many years they had on, they paid the ultimate sacrifice,” Chief Harper said.

Unknowingly, the officers walked into a deadly trap; Mr. Poplawski, wearing a bullet-proof vest, was armed with an AK-47 rifle, a 22 long rifle and a pistol.

The incident began around 7 a.m. in the Stanton Heights neighborhood of Pittsburgh, a blue-collar area made up mostly of single-family brick houses, but also ranch houses like the one where Mr. Poplawski lived with his mother, Margaret Poplawski, 41.

Chief Harper said the police had been called to the house at least twice in the past for domestic disputes.

Although Chief Harper did not identify Ms. Poplawski by name, he said that she had placed the initial 911 call.

The first two officers to respond were Officers Sciullo and Mayhle. Officer Sciullo knocked on the door first, Chief Harper said, and when the door opened he was “immediately met with gunfire,” and fatally shot in the head. He said that Officer Mayhle, who was right behind his partner, was shot him in the head as well.

Their shifts were supposed to end at 8 a.m., the deputy police chief, Paul Donaldson, said in an interview after the news conference. Officer Kelly, whose shift had already ended, showed up to assist his colleagues.

A neighbor, Michele Ostrowski, said she witnessed the scene unfold when the third officer arrived. “He got out of the car and I saw him get shot and he landed on the sidewalk,” she said in a telephone interview, her voice shaking.

Officer Kelly, who was critically wounded, managed to call for assistance. The next officer to arrive, Timothy McManaway, was shot in the hand as he rushed to help Officer Kelly, though he managed to fire at Mr. Poplawski, wounding him in the leg.

For the next few hours, neighbors reported intermittent gunfire as Mr. Poplawski shot from the bedroom window. A fifth officer, Brian Jones, was trying to slip behind the house when he broke his leg climbing a fence, Chief Harper said.

A neighbor directly across the street, Johann Devinney. said she saw the first two officers lying on the ground the moment she opened her front door just after 7 a.m. She quickly shut the door and hid with her husband in the back of the house.

“I knew there was always trouble there, a lot of domestic calls,” Ms. Devinney said in a telephone interview. She said at times she had heard loud music from the house, and from time to time saw police cars there in the past few years. “But I thought it would never escalate.”

Ms. Devinney said Mr. Poplawski lived in the house with his mother and grandmother, but that the grandmother was not at the house at the time of the shooting.

Officers set up in the Devinney’s yard as well as at the house of Ms. Ostrowski, who lives cater-corner to the Poplawskis. The police used the Ostrowski’s Toyota Camry, which was parked in the driveway, as a shield. It now is riddled with bullet holes, she said.

At some point during the standoff, Mr. Poplawski’s mother left the house, Ms. Devinney said, adding that she heard her shouting, “What are you doing with my son?”

About 11 a.m., the police led Mr. Poplawski from the house in handcuffs. Ms. Ostrowski said his thigh and right shoulder were bloodied.

The Pittsburgh Post-Gazette reported on its web site that Mr. Poplawski had called a friend and former high school classmate, Edward Perkovic, from the scene around 8:30 a.m.

Mr. Perkovic said Mr. Poplawski told him that he had been shot in the chest and leg, but that the bulletproof vest he had been wearing had shielded him.

The newspaper reported Mr. Perkovic recounting what Mr. Poplawski told him: “Eddie, I’m going to die today. Tell my mother and friends I love them. This is probably the end.”

Although Pittsburgh is generally unaccustomed to this type of violence, Chief Harper said, the city has recently endured a spate of gang-related activities.

City Councilman Doug Shields said he had been attending a peace rally at Heinz Field on Saturday when he learned of the killings.

— “This event certainly puts a whole different light on that rally,” Mr. Shields said. “What can we do other than pray for the dead and those were hurt? Someone with an AK-47 today was angry enough to use it. It makes me want to be sure we’re reaching out to the community.”