This killer seems much like the one from Charlottesville, and I know from my and my daughter's experience in Athens, GA.
Lock your kids in their bedrooms if you want.
The truth is that we are living in an increasingly hostile and dangerous society. Having had three kids in college recently and having both professional and personal experience on various campuses of major universities, I do not believe your theory.
Sure, there can be crimes, even horrid crimes, on campus, but what happened to this girl could just as easily (and perhaps more so) have happened in a commercial or residential area.
It is absurd to blame this on the college. Rather, it is the fault of the crazed and evil teen who did it.