A fourth person was injured and has been hospitalized, Chief William McManus said during a brief press conference, noting that his information was preliminary.
Based on the review of body camera footage, McManus said a San Antonio agent made a traffic stop and held what appeared to be a casual conversation with the truck driver for a few minutes.
The driver then fired a gun for unknown reasons and opened fire, hitting the officer, McManus said.
The officer retreated backwards as he fired again, killing both the driver and a passenger, and injuring another passenger in the upper trunk. According to the chief, the person who was inside the vehicle and the officer fired several rounds.
The boss said he did not know what motivated the officer to pull the truck.
“He was an officer patrolling here, (a) a routine traffic stop, which in the end turned out not to be so routine,” McManus said.
The killers are believed to be middle-aged men in the late 1920s, McManus said.
The agent, a five-year veteran, was taken to a hospital. McManus said he had no information about his condition that he was not able to speak.
“I will also say that the officer is very, very lucky to be alive at that distance, having been shot in the hand and not anywhere else more vital,” McManus said.