Rates of violent crime and property crime in these four cities combine to make them unpleasant places to live. If you're planning to move to Arizona, avoid these places at all costs.
But as for true crime, in my opinion, I'm sure there's something bizarrely fascinating about seeing the dark depths into which human nature can plunge. Also, perhaps it may be a good way to become more aware of the potential red flags that people with good intentions may be likely to miss.