Despite the cool quote from Kilgore Trout, I must disagree.
In the region that I live in, I can tell you of two women and one cop that were killed by crazed exs. And this is just the stuff that is big in the local news and I read about. In addition, a coworker's daughter was murdered by an ex in FLorida. The US is a big place and I am in a pretty limited region. I would think that this is far more common in big cities.