Yes, exactly. However, aside from mission-oriented or psychotic motivations, there are instances of self-flagellatory impulse killing, during which the discrepancy between professed religious affiliation, complete with set of moral regulations, and sexual deviance and impulse creates lethal cognitive dissonance. These instances are less mission or vision-oriented, and more of an act of personal moral cleansing.
I would be very surprised if law enforcement hadn't considered a missionary type profession as explanation for the transitory nature of this perp (if, that is, the GB4 can be assumed to be connected.) Are you aware of such a line of inquiry? Bible salesmen, door-to-door missionaries? People connected to a specific congregation aligned along the East Coast?
The convenience of acquisition alone does not explain the consistency of the victim's profession.
There is an excellent article title “Beyond the Boardwalk” that was published in 2007 that gives quite a few details concerning the initial investigation of this case. One of the moderators here started a thread with the link to the article and I thought, for convenience, I'd post the link as well.
Towards the end of the article (page 5 or so) it lists details of the various POI's that were questioned in the initial stages of the investigation. One of the individuals mentioned would appear to fit the profile of a religious motive. So the answer to your question would appear to be that police did probe the missionary angle early on.
With new information coming to light a decade later it may be possible to theorize a bit more about the profile of the killer. In an earlier post I mentioned that a reporter for NJ.com recently published information concerning the fact that Ms. Raffo, the last victim, had left a customer in a room at The Trump Taj Majal casino at 5:00 am in pursuit of drugs.
The importance of this new revelation (at least to me) is the fact that Ms. Raffo was probably not plying her trade at this time and possibly accepted a ride from an individual who she knew well enough to be persuaded to get in a car with. Afterall, someone did transport her, or her body, to The Golden Key. Other than a taxi cab ride, I doubt that Ms. Raffo would get in a car with a stranger unless she viewed him as a potential paying customer. But indications are that she was not seeking a customer.
Rather, she was seeking drugs. So I'm speculating that she accepted a ride from an individual who was a regular in the area and who related to Ms. Raffo ( and possibly a few of the other victims) as kindred spirits lost in the local drug scene. An individual who would not be out of place at Papa Joe's restaurant. Nor would they be out of place at The Atlantic City Rescue Mission.
I find it interesting that the depot for The Ocean Rolling Chairs company is located right in the area at S. Carolina Ave. Lots of shady individuals work all hours of the day (and night) pushing those carts up and down the boardwalk.
In a recent Websleuths's podcast concerning the AC4, John Kelly, a recognized criminal profiler, made a point not often discussed. He found it interesting that, aside from all the talk about the missing shoes, all four victims were found fully clothed (sans shoes, of course). He thought it peculiar that discovering the bodies clothed may indicate that the killer didn't have sex with the victims, at least not in the conventional sense.
So one could theorize that neither the killer nor his targeted victims were seeking sex at the point of first encounter. Which may fit with the 'personal moral cleansing' angle that you are talking about.
As always, just my opinion.