The Kitchen Khemist — Mathiya Adams

Mark MacFarland, a former detective with the Denver Police Department, always knew that the Mile High City had a seamier side, but it had never been his particular playground. After all, despite its lurid reputation, Denver's kink community was relatively peaceful and unobtrusive.
 
That all changes when Thorne Rose, a submissive participating in a BDSM "scene" dies. At first the death is ruled accidental…but that all changes when the ME discovers poison in the young lady's body. Then suspicion falls on the man who was beating her at the time, David Von Hoffman, also known as the Kitchen Khemist.
 
Did he really kill his submissive? Or is someone else responsible for poisoning Thorne Rose? MacFarland finds himself immersed in the exotic kinky world of Denver's BDSM community as he tries to discover if his client is an innocent man or a sadistic killer.  
The Hot Dog Detective stories follow the adventures of Mark MacFarland, a former Denver Police Department homicide detective. When MacFarland's wife was killed, MacFarland began drinking, lost his job and home, then began living on the streets. After several years, he managed to sober up and start a new career. Now MacFarland operates a hot dog cart near the county jail and courthouse. But his crime-solving days aren't over, since in addition to providing his former homeless friends with free food, MacFarland finds himself solving crimes that the police can't solve.

The Kitchen Khemist is part of a series. Each book can be read independently, but if you want to read them in order, just follow the alphabet.