It happened around 8 p.m. Monday on Liberty Road near Homestead in northeast Houston.
Officers responded to a report of a body lying in the roadway and found the man near a vehicle that had crashed into a ditch, according to Houston police.
There was no word on the man's identity or if someone may have seen the shooting take place.
The area where it happened is adjacent to Union Pacific Railroad's Englewood rail yard, which is monitored by multiple video surveillance cameras.
Investigators were reviewing cameras in the area in hopes of finding out what exactly happened and a description of the suspect.