My point, below, was simply that if people want to kill people and don't care if they get killed or caught they're going to kill people. The existence of guns facilitate certain kinds of crimes, but there are many other options. Large motor vehicles could be quite effective, too, and don't require much creativity or skill. More creative options also exist.
Obviously security measures can protect specific locations and minimize the likelihood of certain kinds of violence at those locations - hard to bring a gun past security at an airport, easy to shoot up the check-in desk area or drive your SUV into the crowd standing outside - but I assume we don't want all of our spaces to have that kind of security. There's a catchy phrase for that kind of state, which usually has bad connotations.
College campuses are not daycare centers, they are places where large numbers of adults live and study and work. While some, especially those in dense urban areas, are more closed to the outside world, many are quite open. You know, like shopping malls are, another set of places where large numbers of people congregate with minimal security present and where someone who didn't care if he got killed or caught could successfully kill a lot of people.
None of this is an argument in defense of whatever specific measures the campus took yesterday, it's just about the notion that there are any general security measures any of us would want applied which could prevent this kind of thing. You can't. At most you can divert it.
