I’m not sure there is an easy link between movies and gun violence. I think the link is between the violence and the publicity. Those like James Holmes, who feel the need to arm themselves, may also feel a deep, inchoate insecurity and a need for validation. Whenever a tragedy like this takes place, it is assigned catchphrases and theme music, and the same fragmentary TV footage of the shooter is cycled again and again. Somewhere in the night, among those watching, will be another angry, aggrieved loner who is uncoiling toward action. The cinematic prototype is Travis Bickle of “Taxi Driver.” I don’t know if James Holmes cared deeply about Batman. I suspect he cared deeply about seeing himself on the news.