Movies aren't accurate depictions of reality unless you watch certain kinds of movies that are trying to point out something about culture (like Natural Born Killers, which most people didn't get, because people are stupid and don't understand satire and cultural criticism, which ironically just proves the social critic right).
Let's put it this way, guns are just inanimate objects. They don't do anything unless a person makes them do something. They don't call out to you saying things like "hey, pick me up and shoot that person over there". It takes a person to put a gun into some sort of action. So the root of the problem is whatever is driving the person to pick up the gun and massacre people. The root of the problem is not the gun itself. That's missing the entire reality of the situation. To solve this problem, we must address the root of it and not the mere symptom.