Love and Punishment

We know from early on who the killer is, so this isn't so much a whodunnit as it is a psychological thriller with a serial killer, BTK, that appears to have a personal vendetta against Detective Tony Parglietto and is willing to use Tony's boyfriend, newspaper reporter Flynn, to get his message across.
The two MC's acted like grown ups for the most part which is always appreciated, without overwrought drama and there is a good supporting cast of secondary characters. Just a word of warning, the killer is a brutal psychopath and the crime scene descriptions and some on page torture may be a bit much for squeamish readers.