Found: Murder mystery. Serial prostitute murders investigated by two "buddy cop"/ police detectives, written in the late 1990's or earlier

I read a book about two white male cops. They are tracking a serial killer who murders female prostitutes. The killings are usually done by strangling the women, after or during the end of sex. The murder scenes are described somewhat provocatively i.e. mention of arousal and naked breasts, but not so graphic as to be lewd or essentially XXX depictions.

The first cop has a girlfriend who is a Wiccan. She explains to the second cop, her boyfriend's new partner/friend that Wiccans don't worship the devil and that she even prays. This is not an important element to the overall story, but adds some intrigue or allure to the girlfriend as a secondary character.

The second cop dresses nicely and does not have a girlfriend at the beginning of the novel. The narrator (usually the 1st cop, I think or 3rd person) describes his style of dress as someone who doesn't wear clothes off the rack. It is described that he usually has them tailored and they are designer. He is described as being in really good shape and possibly a martial artist. I remember at one point he may have delivered a flying karate style kick. I also think at some point during the story the first cop and his girlfriend set the second cop up with someone. Maybe she was a schoolteacher or librarian. It was implied that they were hitting it off and that they would possibly get married and everything would end happily ever after. I remember a meal around the table at the home of the Wiccan girlfriend where the two couples are enjoying each others company.

**Spoiler**

In the end it is revealed that the second cop is the serial killer. Initially the two cops apprehend someone else. The reader is lead to believe that the story is all but wrapped up. The first cop happens upon some clue and realizes the truth. There is something in the background of the second cop that tips him off. I believe it had something to do with some murders that happened while the second cop was in the military. I believe the explanation was that the second cop was traumatized as a child. His mother possibly turned tricks while he was young. She may have been his first kill. He then went off to the military to escape his past.

Also the second "cop" is not actually a cop. He is an investigator from a public law office.

I believe the second cop was a MP-military policeman while he was in the service.

I think the Wiccan girlfriend's name may have been Sarah.

I don't remember the final resolution being violent. I think the first cop reveals his deduction and presents his evidence to his police partner/friend in an amicable manner. I think it is kind of a, turn yourself in on your terms rather than make me prove this type of situation. They may do it over a beer at one of their homes and the story ends without the reader knowing what the murderer does.

I think the first cop with the girlfriend had longer hair.

I think the main suspect may have been an unsuccessful businessman or lawyer. The suspect is married. I believe his wife is described as being unkempt and uninterested in having sex with him. He frequently pays for prostitutes. Once he becomes a suspect his wife is made aware of how often he has sex with prostitutes. I believe she is somewhat affluent. Near the conclusion of the story she confronts him about the "diseased whores" that he sleeps with instead of her. I believe she either kicks him out of the house at this point or leaves him quietly contemplating this revelation. She may also say that he will be cutoff financially.

He may have committed suicide.

This of course sounds like something of a plot I have probably seen in a movie or on some police procedural show...

I found a Michael Connelly book called The Concrete Blonde that has some similar story elements. I haven't read it yet.

I think all of the strangulations were done with a scarf (blue??) or handkerchief/neckerchief. I think this was the damning evidence that initially got the wrong man convicted (or maybe a stocking or pantyhose with them still being an association to his mother).

I believe the police found the strangulation object somewhere in the residence, automobile or office of the suspect. Possibly they found a drawer or box of them.

Once the first cop realized he believed his partner was the actual killer he searched his home or car and found the actual scarf/kerchief.

I believe he then questioned the actual killer about it's significance. At this point the partner/killer/friend revealed that his mother always wore a similar item when ever she was going out or returning with Johns.

I finished The Concrete Blonde. Reading it helped cement (no pun intended) that in the book I am looking for the murderer probably used stockings to strangle his victims. Looking into it I have found that the Boston strangler of the 1960's had a similar m.o. , but he was not a policeman. The serial killer Gerard John Schaefer was a cop and preyed on victims that he referred to as whores, but they were not actually prostitutes. He had stories published as roman a clef style around the same time period that I read the book in the mid to late 90s.

Homicide Game by David Hunter.

https://www.librarything.com/work/8576989/book/215114788