FBI documents made public this week reveal the high-roller gambler who opened fire on concertgoers on the Las Vegas Strip had lost tens of thousands of dollars while gambling weeks earlier. One gambler told the FBI that gunman Stephen Paddock was very upset about how the casinos had treated him and other high-rollers.
https://apnews.com/article/las-vegas-shooter-9bbd180cf3aa6d3ea1a37bbfb7144ae1