SALT LAKE CITY - After a gunman opened fire in a Colorado movie theater, killing 12 people and injuring dozens, many are left wondering what triggered the mass shooting. Is violent media to blame for his actions?

24-year-old James Holmes allegedly entered an Aurora, Colo., movie theater on Friday morning and fired several dozen rounds into a theater full of people attending an early-morning screening of "The Dark Knight Rises," leaving at least 12 dead and 50 wounded.