The unveiling caught the eye of Chris Adzima, a former eBay programmer who had been hired at the Washington County Sheriff’s Office to work on an iPhone app that deputies use to track inmates’ behavior. His agency had hundreds of thousands of facial photos already online and no real way to analyze them. Using Amazon’s AI, he got a system up and running in less than three weeks.

“They didn’t really have a firm idea of any type of use cases in the real world, but they knew that they had a powerful tool that they created,” said Adzima, a senior information systems analyst who works in a small cubicle at the sheriff’s headquarters. “So, you know, I just started using it.”

Deputies immediately began folding facial searches into their daily beat policing, and Adzima built a bare-bones internal website that let them search from their patrol cars. He dropped the search-confidence percentages and designed the system to return five results, every time: When the system returned zero results, he said, deputies wondered whether they’d messed something up. To spice it up, he also added an unnecessary purple “scanning” animation whenever a deputy uploaded a photo — a touch he said was inspired by cop shows like “CSI.”