The father of the Oregon community college shooter said Saturday that he "had no idea that he had any guns whatsoever" and called for more restrictions as he questioned how his 26-year-old son obtained as many as 13 firearms. "How on Earth could he compile 13 guns? How can that happen?" asked Ian Mercer, the father of Christopher Harper-Mercer, who killed nine people and injured nine others in the shooting at Umpqua Community College in Roseburg.