Nocturne for Madness (Thomas Haftmann) by Robb White

This was one hard to read novel. Not because of the writing, but the fact it was so dark and sometimes shocking I had to put it away. Haftmann is not the light-hearted hero like Spenser or Elvis Cole and the bad guy is not an amusing mobster like Joe Broz.
Ex-cop Haftmann is a drinker, a gambler and mentally unstable. He's also on the trail of a serial killer that kills women who he picks up from swinger sites. Working with, but still hated by the police and FBI we follow Haftmann's descent further into insanity on his hunt for the killer.
The writing is dark and lyrical, gruesome details are not spared at all. The atmosphere unsettling.
So, if you that Andrew Vacchs writes too light-hearted and Spenser novels are too Disney for you, this is your book.