Just going to step way out on a limb hear and say: For more than a year and a half I have been convinced that there is no real serial killer in these cases. I have felt for a very long time that there is some organized group that is involved and that they have the goods on enough people, some big wigs and some working class stiffs, to call in a debt (so to speak) in order to get them to provide the necessary services, be it medical, removal, storage, or disposal.
These parties or parties of this type and held at different large and exclusive homes might have been where things went too far with the paid sex worker/workers. Then someone makes a few discreet calls/phone tree of sorts and bam...problem solved. Now, time to plan the next big shindig and make sure your latest ad dissuades any guests with anger issues and substance use before partying.
Of course, it could still be one guy/guest or a few together who push the envelope but if they are not at their own playground then the host/hostess still has to have a few helpful folks to get rid of any problem that might get their little business shutdown or exposed. Ironic how they advertise with such impunity, though isn't it?
Just remember, the men who like being dominated are often men whose job or home-life requires them to be the take charge, works hard and well under-pressure and be the number one decision maker. In his free time, he wants someone else to tell him what to do. These guys, often being in powerful positions, cannot afford to be exposed so they are easily blackmailed or become part of being silent about the wrong-doings of others. They know if they speak up that not only does their little fantasy escape go away/get shut down but they will be publicly outed for their fetishes and law-breaking.
Now, there is one other theory I have kept on the back burner. That some of the girls, possibly as early as MB, were out to expose the creeps and one of these fetish creeps wasn't having any of it. From my understanding of reading the escorts reviews of these guys, many girls will participate in outing the wackos & creeps. Perhaps all of the GB4 on one occasion or another took the time to review or to publicly ridicule or out the the same freak. Maybe, he invited them out to a fake or even a real party such as the ones in Massapequa and Fire Island.