A gunman wounded two police officers and killed two others before being fatally shot Monday near the campus of Texas A&M University in College Station. NBC's Brian Williams reports.

click2houston.com Brian Bachmann, an elected constable in Brazos County, Texas, was serving an eviction notice when he was shot and killed Monday, College Station police say.

Updated at 10:47 p.m. ET: A police constable and a civilian were killed when a gunman opened fire Monday near the campus of Texas A&M University in College Station. The gunman died after a gunbattle with police, authorities said.

Police in College Station, about 100 miles north of Houston, responded shortly after noon local time (1 p.m. ET) to a home near George Bush Drive along the southern boundary of the university after gunshots were reported, Assistant Police Chief Scott McCollum said. When officers arrived, they came under fire and shot the suspect during what McCollum described as a 30-minute shootout.

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Police identified the gunman as Thomas Caffall, 35, and the bystander killed as Chris Northcliff, 43, of College Station.

Officers found Brian Bachmann, 41, the elected constable for Precinct 1 in Brazos County, on the ground and began performing cardiopulmonary resuscitation. Bachmann, who had gone to the scene to serve eviction papers, was pronounced dead at an area hospital, McCollum said.

College Station city spokesman Jay Socol said authorities were still investigating Caffall's background. It was unclear whether Caffall was renting the home or was being evicted for nonpayment of a mortgage, he said.

Bachmann, a Brazos County sheriff's deputy from 1993 until he was elected constable in 2010, "was very close to everyone in law enforcement here," McCollum said.

"He was a pillar of this community," McCollum said. "It's sad and tragic that we've lost him today."

Officials said the wounded included a 55-year-old woman, who underwent surgery, and College Station police officer Justin Oehlke, who was in stable condition after being shot in the leg.

Officers Brad Smith and Phil Dorsett were injured by what police called gun shrapnel. Smith was treated at a hospital and released and Dorsett was treated at the scene.

"We had officers respond to a 'shots fired' call," McCollum said at a news conference. "Once the officers arrived, they began to trade fire. The officers defended themselves and called in additional officers."

Investigators were "working through their emotions," McCollum said.

"You can imagine, as close as he was to all the officers in this area — these are the officers who are working this case," he said.

Campus officials issued an alert early Monday afternoon to faculty and students for an "active shooter" two blocks southeast of the university, which houses former President George H.W. Bush's presidential library.

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Melinda Ryan, Charles Hadlock, Terry Pickard and Julmary Zambrano of NBC News, and Reuters contributed to this report.

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