The robbery happened at The Coyote Mart, located in the 3000 block of W. Marina Bay Drive, just before 7 a.m., according to League City police.
Police said a customer found the clerk unconscious on the ground outside the store, with his hands taped behind his back and tape covering his mouth.
The video above is from a previous report.
The clerk, who police identified as 46-year-old Rafiq Maknojia, was unresponsive and taken to a local hospital for treatment. He is now in stable condition, police said.
LCPD released surveillance images of the suspect, who was wearing a black hoodie and dark jeans at the time of the robbery.
The suspect can be seen on video displaying a handgun before moving behind the counter and stealing money from the cash registers, according to police.
Police believe the clerk was injured while trying to get away from the store.
LCPD is asking anyone with information about the robbery or the suspect to contact Detective Yount at 281-554-1849.