It all went down at the Ranchito Taqueria on S. Gessner near Bellaire Boulevard last night, according to HPD.
Houston police said an armed man in a mask came inside the restaurant, demanding money and wallets from customers. However, as he was leaving, one of those customers shot the suspect.
None of the other people in the restaurant were injured during the incident.
Investigators said the suspect ended up not having a real gun.