Cormani Adams was arrested Friday after he allegedly held two people at gunpoint in the 18000 block of Pinson Drive.
The Harris County Precinct 4 Constables' Office said the victims told Adams they didn't have any money on them.
Adams, in turn, allegedly fired a round into the ground before running off on foot.
Deputy constables arrested Adams minutes after the alleged victims called 911.
Adams is facing a felony aggravated robbery charge and is being held without bond.