I noticed that many of the less than great reviews are based on just watching the pilot, or a few episodes. After watching the first few episodes I wondered where it was heading, and was not yet hooked. But as I keep watching, every episode make me like it more. There is the weekly murder mystery, as well as the ongoing backstory.
While some people might compare this show to Criminal Minds, it's different. With Criminal Minds it is more of a good guys catch bad guys type of show. The last show I like as much as this was The Mentalist, the main character had a way to get into people's minds, and is not afraid to take it to the extreme. With Prodigal Son, much like the Mentalist, the main character has a perspective on the criminals based on personal tragedies.
I do not watch much television. Every year there are only a few shows that I make a point of watching. Prodigal Son has become one of those shows for me