I honestly can't believe you're using John Lott as a reference for why guns are good. He's a know joke, and his "facts" are made up. It's a miracle the GOP even uses him, but it makes sense considering it's impossible to find anyone credible who would actually advocate for guns.
His facts come directly from FBI statistics. The only joke is people who attack him not for the truth of his research, but because his conclusions go against their beliefs. Which is exactly what you are doing. His methodology has stood up to peer review since the 90s.