As the closing act of the three-day, open-air Route 91 Harvest Music Festival took the stage the evening of Oct. 1 on the Las Vegas Strip, a 64-year-old man used a sledgehammer to smash out two windows in his suite at the adjacent Mandalay Bay hotel. His perch on the 32nd floor gave him a clear field of fire on the 22,000 or so concertgoers below. He took aim with one in the arsenal of guns in his room and opened fire. The shooter's intent was clear – he wanted to create as much carnage as possible. The crowd below remained oblivious to the threat 100 meters (328 feet) above and 400 meters away until bullets began raining down. The attack, which left 59 people dead and more than 500 hurt, was certainly well-planned.