Investigators said the man entered the drug store in the 120 block of S. Friendswood Drive on September 28, around 4 p.m.
The robber pulled out a weapon and handed the victim a note demanding prescription pain medication.
The man then fled the scene in a blue over tan Ford Expedition.
The suspect is described as a white male, with short dark brown hair, standing between 5 foot 6 and 5 foot 10, and weighing approximately 160 pounds.
He was wearing a black baseball cap with the word "Police" on the front, sunglasses, a black t-shirt, tan pants and white shoes.
If you know who he is, you may be eligible for a $5,000 reward. You can make an anonymous tip by calling 713-222-TIPS.
You can also submit your anonymous tip online at www.crime-stoppers.org.
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