The homicide of a Churchill Downs worker, 48 year old Adan Fabian Perez of Guatemala, the day after Derby has raised questions about the culture of backside work at racetracks.Frank Agrinsoni is the backstretch activities coordinator for Churchill Downs, where he works with the Kentucky Thoroughbred Association and the Horsemen's Protective and Benevolent Association. He joined us Friday on Byline to talk about the lives of backside workers, and the impact of the recent homicide on the people who work there.WFPL's Devin Katayama also sat in on the conversation; he recently reported on immigrant workers at the racetrack. We listened to his piece and he explained more about what he learned.