Shaurn Thomas walked free from prison May 23 after serving 24 years for a murder he didn’t commit. His case is a potent reminder that innocent people get convicted; that our rules and adversary system don’t always provide criminal defendants fair trials.

Shaurn was convicted of participating in the murder of Domingo Martinez on November 13, 1990. At trial, a witness testified he and Shaurn were in a gray car accompanied by three other men in a blue Chevy. The occupants of the blue car staged a fake accident with Martinez, whom they had been hunting, and then shot and killed Martinez. But after 24 years, the truth finally emerged. There was no “gray” car, as prosecutors alleged. There was only one car—as multiple eyewitnesses told police. But Shaurn would spend 24 years of his life in prison before that truth became known.