Charles Galloway, 47, was a 12-year veteran and a field training officer, Harris County Precinct 5 Constable Ted Heap said Sunday morning.
Galloway was making a traffic stop on a newer-model, white Toyota Avalon around 12:24 a.m. (1:24 a.m. ET), Houston Police Chief Troy Finner said.
“Witnesses describe the suspect as Hispanic male (and) say that he got out of his vehicle and immediately fired upon the deputy multiple times, striking him and then drove off,” Finner said.
A witness told police an “assault-type weapon” was used in the shooting, the police chief added.
“This is senseless. It makes no sense whatsoever.”
The Houston Police Department and Harris County Constable Precinct 5 escorted the slain deputy from Memorial Hermann-Texas Medical Center to the medical examiner’s office.
Galloway sometimes volunteered to work the night shift to make himself available for field training, Heap said.
Galloway is survived by a daughter, his sister and “the numerous officers here in Precinct 5 who are trained by him,” mentored by him “and who are going to miss him tremendously,” Heap said.
As of mid-Sunday morning, no arrests had been made. The motive remains unclear.
Jason Rivera was responding to a domestic disturbance call when he was gunned down Friday night.
CNN’s Keith Allen contributed to this report.