Mesquite, Nevada (CNN)He seemed so ordinary, just another house-hunting retiree, when he strolled with his girlfriend into the sales office of the Sun City development in late 2014. The agents had just what Stephen Craig Paddock was looking for -- a 2,000-square-foot, two-bedroom stucco rambler on a cul-de-sac. Other houses might offer bigger floor plans, but the one on Babbling Brook Court had two big selling points: a commanding hilltop view and, perhaps most importantly, privacy. Neighbors lived to the left and right, but none behind the home. Paddock quickly said he'd take it. He stood about 6-foot-4 but came...