What happened

The investigation of a violent assault on a security guard on a train platform outside St. Louis, Missouri, by two culprits drew a blank, until the police officer in charge of the case resorted to facial recognition to try and solve the case.

Despite the fact that the suspect's face was obscured by clothing and a mask, the AI-powered software generated several potential matches, including Christopher Gatlin, a 29-year-old father of four with no prior history of violent crime or likely connection to the incident.

Detective Matthew Shute proceeded to build a case against Gatlin, conducting a photo line-up in which the victim was asked to identify his attacker. This lineup was later deemed unfair by a judge, who ruled that it did not meet necessary standards for reliability.

Gatlin was arrested and jailed for over two years while he fought to clear his name. 

Why it happened

Detective Shute ignored warnings about the inaccuracy and unreliability of AI-generated photo matches, as well as Pagedale's facial recognition policy, which explicitly warned that such technology is "nonscientific" and should not be used as the sole basis for arrests, and proceeded with an arrest anyway.