Williamson -- who tells us he's a former Marine -- stops in at PAK's Food Store every night for a couple of hours to help the store owner stock shelves. On Wednesday night he was in the back freezer when he spotted trouble.
"When I came out of the freezer, they were walking in the hallway, he was pointing it around," Williamsonon recalled.
In surveillance video captured by store owners, two men can be seen walking in with their faces covered. Moments later, Williamson walked straight out of the front door.
"I walk my way out the door, get their attention, which is the whole idea to begin with," Williamson said.
Once outside, Williamson held the door shut while he called police. The suspects grew more agitated with him, kicking and screaming, then bam! One of them shot at him through the glass door before running off.
Other customers are glad Williamson is OK.
Customer Earnest Welcome said, "It could have been me because I always come in here, you know. "
"Thank God for good Samaritans," said customer Frosty Al-Oboudi.
The good Samaritan credits his military training for bravely taking on the robbers, and says he'd do it again, but hopes, of course, that he doesn't have to.
"Those are peoples' lives, sweetheart," Williamson said. "I'd do the same for y'all."
Police have only a very basic description of the suspects. They are described as being about 15 years old. Anyone with information is asked to call Crime Stoppers at 713-222-TIPS.