According to the Galveston Police Department, the shooting happened in the 1700 block of 55th Street at about 3:45 p.m.
Police said that during the stop, an occupant of the vehicle was injured after an officer discharged his firearm.
Officers said they immediately rendered first aid to the injured man at the scene. Hel was then taken by EMS to the UTMB Emergency Department, where they were later pronounced dead, officials said.
Authorities said the officer involved has been placed on modified duty pending the outcome of the investigation, in accordance with department policy.
Officials said that details are currently limited and that the Texas Rangers and the Galveston County District Attorney's Office are leading the investigation.