Police say the deputy was shot outside Club Rodeo early Sunday; a second man faces a related charge.
AUSTIN, Texas — A 38-year-old man has been charged with capital murder in the fatal shooting of Caldwell County Precinct 3 Deputy Constable Aaron Armstrong, who was working an off-duty security job outside Club Rodeo in North Austin early Sunday, Jan. 4, police said.
Authorities said the arrest came hours after the shooting and capped a rapid, multiagency search. The case has drawn citywide attention because Armstrong was a peace officer and because investigators said the attack was recorded on the deputy’s body-worn camera. Austin police labeled the killing the city’s third homicide of 2026 and said additional enforcement will follow in the area while detectives finish key interviews and evidence reviews.
According to Austin police, officers were called just after 2 a.m. to the parking lot of Club Rodeo at 9515 North Lamar Blvd., where they found Armstrong with gunshot wounds. He was taken to a hospital and pronounced dead. Investigators said the suspected gunman fled in a vehicle but was arrested at about 3:45 p.m. Sunday by the U.S. Marshals Lone Star Fugitive Task Force with assistance from Austin police air and K-9 units and the Texas Department of Public Safety. At a Monday briefing, Austin Police Chief Lisa Davis said Armstrong tried to de-escalate a confrontation moments before he was shot, calling the attack “an execution.”
Police identified the accused gunman as Thomas Vences, 38, and said he faces a capital murder of a peace officer charge among multiple counts. Investigators said surveillance video, body-camera footage and witness statements support the case. A second man, identified by police as Ronaldo Ernesto Colindres-Simon, 22, was arrested on a felony assault on a peace officer charge after authorities said the getaway vehicle struck part of Armstrong’s body as the suspects drove off. Officials did not immediately release the full probable cause narrative or a motive. Detectives said they are still gathering digital evidence and canvassing for additional witnesses from inside and outside the club.
Armstrong joined the Caldwell County Precinct 3 Constable’s Office in October 2024, officials said. He was working a private security shift at the North Lamar venue when the shooting occurred. Club Rodeo sits along a busy commercial corridor in North Austin. The killing came during a violent start to the new year for the city; police have opened three homicide investigations in the first five days of 2026, including the nightclub case. Records show Vences has prior criminal cases in Travis County. Police said the investigation remains active and urged anyone who saw the encounter or recorded video in the parking lot to contact detectives.
Prosecutors said the capital murder count carries the state’s most severe penalties. Booking and first appearance details for Vences were not immediately available Monday evening. Police said a formal affidavit will outline evidence recovered from the scene, including casings and video clips, and from follow-up searches. The department planned additional patrols around nightlife corridors this week while homicide detectives complete interviews and the medical examiner finalizes results. Officials said they expect to release more information after a scheduled case review and once next-of-kin notifications and internal administrative steps are finished.
Outside the precinct office Monday, a small memorial of flowers and flags began to grow as law officers in dress uniforms filed in and out. “Deputy Armstrong was a steady presence,” a Caldwell County constable’s supervisor said, adding that colleagues rode in convoy to Austin after the shooting. A patron who arrived at the club after 2 a.m. said he saw police tape stretching across the lot and a helicopter circling overhead as officers interviewed witnesses. Nearby businesses reopened by midday, though several kept security gates pulled down while technicians finished collecting evidence.
As of Monday night, the homicide investigation remained open, with additional court filings expected this week and a police update planned after detectives process body-camera footage and lab results. The department said it would release supplemental case documents as they are approved.
Author note: Last updated January 6, 2026.