ORLANDO, Fla. — Omar Mateen killed 49 people and injured more than 50 others at Pulse nightclub in Orlando on June 12, 2016. Ron Hopper was the FBI's Assistant Special Agent in Charge when his phone rang before sunrise that morning. WATCH WPTV'S COVERAGE BELOW: 10 years after Pulse nightclub shooting, lead FBI investigator reflects on the case "It's bad. There's over 20 dead. One of the officers. And I said I'm on my way," Hopper said.