Let me get this one out straight away, M. William Phelps claims to be a "journalist". He's more like a cheesy reality star, with very little star quality. His corny presentations are perhaps only undercut by an even worse musical underscore - and that by an even cornier "inside serial killer" with the "codename" of 'Raven.'
It is completely un-watchable, lowest denominator, drivel-formed television programming. I don't even know how the good name of Discovery even agreed to attach itself with this terrible stuff. I'm used to American cheeseballing faux-reality TV (with poorly constructed stuff like "Cheaters" or "Lizard Lick Towing") - but this one tries so hard to pass off as a serious crime show that it ends up being toe-curlingly cringe-worthy.
Avoid it at all costs if you're a serious lover of crime documentaries. It will waste several hours of your life if you try to "give it a go" (as did I). 4 episodes (from a selection of seasons) and it never gets any better - if anything, it gets worse.
The only thing this might be good for is driving up the profits of your local liquor store as you'll find yourself needed a liter bottle of Jack Daniels to make it through... though at least the show does give you some good tips and choices on how you'd like to bump off Phelps and the rest of the production team for inflicting this upon society.