Witnesses told Harris County sheriff's deputies that a man was standing on Wallisville Road near Normandy Street when he was hit by a black pick-up truck that was headed eastbound at 11:45 p.m. Monday.
The man was reportedly standing right along the divider line that splits the eastbound and westbound lanes of traffic when he was hit, deputies said.
The driver of the pickup truck fled the scene after hitting the man, witnesses said.
Authorities said witnesses were trying to wave down a deputy who was leaving a station, but the deputy also hit the pedestrian after he was already lying in the roadway.
"The deputy, as he was being flagged down by these witnesses, then struck the pedestrian who was already lying in the roadway," Major Susan Cotter said.
The man was pronounced dead at the scene.
Deputies are looking for surveillance video of the crash. Investigators said they collected debris at the scene that could help identify the driver of the original striking vehicle.
"If anybody knows anything about this, we encourage them to come forward and to call our dispatch at 713-221-6000," Cotter said.