What led 64-year-old Stephen Paddock to carry out the worst mass shooting in modern U.S. history is now the number one question investigators are trying to answer. Criminologist Dr. Casey Jordan said reports that Paddock was gambling $10,000 a day before the massacre may be a clue. In surveillance video from five years ago, paramedics can be seen examining Paddock after he claimed he was injured in a slip and fall at the Cosmopolitan Casino. He sued for $32,000, but the case was tossed out. #InsideEdition
