A gunman opened fire on concertgoers at a country music concert on the Las Vegas Strip Sunday night, killing at least 20 people and injuring “in excess of 100” before being killed by authorities, police said. Witnesses told the Associated Press that they could see muzzle flashes coming from the Mandalay Bay Hotel and Casino’s high floors and described the sound of automatic gunfire. Police said they confronted the gunman on the hotel’s 32nd floor. Police said the gunman was a local resident but did not identify him. The shooting appeared to take place near the Route 91 Harvest Festival, a three-day country music ... (full story)