I have been watching re-runs of Criminal Minds episodes,and ran into one I immediately recogni 2zed,both because it was a good story,and because the guest star (Andy Milder) flat blew it out of the water with his acting ability as the retarded serial killer/torturer that goes after girls that remind him of his brother's wife.
The story itself is very good,just like all the story lines on this series,but this actor is something special.
If you care to look it up,it is Season 7,Episode 2. The episode title is "Proof".
It is episodes like this that make me thankful I turned down the chance to become a cop.
This type of show may not be your "thing",but I can guarantee you that you will be impressed by the writing and the acting.