I'm going to be honest, I only finished this book because I wanted to see how the case was resolved. I felt like this novel was just a clumsy vehicle for the author to show off how much he knows about criminal psychology and profiling (which was his former profession, I believe).
I didn't care about the main character (Robert) and none of his emotional reactions felt real to me. He is one of those too good to be true protagonists, great at everything and faux humble to boot ("I read a lot"). Normally I can overlook that sort of trope if the dialogue and supporting characters are fun and entertaining, which was not so in this case. The conversations read like lectures half the time - especially when he was speaking to Garcia, his rookie partner. The author used his newness as another way to throw infodumps out in large pieces.
Honestly, I was more interested in D-King's underground kingdom than anything Robert was doing.