"Our hearts and prayers go out to the families and this is just a senseless tragedy," said Courtney Clark, Caffall's sister, reached Monday evening at her mother's home in Navasota, about 20 miles to the south. "We are just distraught by the havoc that he has caused. We're shocked."
She declined additional comment.
Police spokeswoman Rhonda Seaton said Chris Northcliff was outside the home when he was shot, as was the wounded woman, whose name had not been released by Monday evening.
The woman was hospitalized in serious condition following surgery. One of the injured officers, Justin Oehlkee, was treated for a gunshot wound in the calf and was in stable condition, Seaton said. Two other officers Brad Smith and Phil Dorsett, were treated for "shrapnel injuries" and released, Seaton said.
Police declined to speculate on a motive for the gunfire.
The shootings prompted Texas A&M to issue an emergency alert warning students and residents to stay away from the area. Most of the university's 50,000 students were not on the campus about 90 miles northwest of Houston because the fall semester doesn't start until Aug. 27, university spokeswoman Sherylon Carroll said.
Diana Harbourt, 27, who lives about a block from where the shootings happened, said she heard five loud popping sounds from a back room of her home looking out her front door to see an officer park his vehicle on the street and crouch in front of another vehicle.
"We heard him exchanging some words with the person and then shots being fired," Harbourt said. "And then we heard more sirens and more officers and fire trucks came and they were keeping their distance, kind of slowly moving in. More officers showed up and told us to stay inside."
Officers, meanwhile, were dealing with losing someone McCollum called a respected colleague.
"Brian Bachmann was very close to everyone in law enforcement," McCollum said. "He was a pillar in this community, and it's sad and tragic that we've lost him today."
Bachmann worked more than 19 years in law enforcement, according to the Texas Commission on Law Enforcement Officer Standards and Education. He started out with the Hempstead Police Department before spending most of his career with the Brazos County Sheriff's Office. He had been a constable since January 2011, after winning election to the post the prior November.
In a February 2010 candidate profile in the Bryan-College Station Eagle, the married father of two said he wanted to bring "constables back to the community" by actively patrolling neighborhoods to discourage crime.
Constables are law enforcement officers similar to sheriff's deputies who are elected to serve in specific county precincts. They primarily serve warrants and official paperwork or act as courtroom bailiffs.
Texas Gov. Rick Perry, an A&M alumnus, said at an event in Florida that his "prayers are with any of those that have been injured." A&M President R. Bowen Loftin issued a statement calling Monday a "sad day in the Bryan-College Station community."