LUBBOCK, Texas - An alert grandmother who knew what her grandson had been planning may have stopped a mass shooting before it could happen. Special agents with the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives arrested William Patrick Williams, a 19-year-old man from Lubbock, Texas, the U.S. Attorney's Office of the Northern District of Texas announced Friday, CNN reported. The man, according to federal officials, had bought ammunition and an AK-47 and had rented a hotel room to plan a mass shooting, CNN reported. He had wanted to "shoot up" a hotel and "then commit suicide by...