Hi all, I've been reading and decided to respond for the first time today. Thanks to all for letting me be a part of this community.
I think, if the AC murders are related, they were probably his first in the line of serials. I suspect he strolled the "track", which is the area a block off the boardwalk where girls work. It is very easy to drive down the road and pick up a girl off the street. I think he probably told the girls he would pay for an hour or more and asked to go to a hotel. The Golden Key is about a 10 minute drive from the boardwalk, and is known to be a place for prostitutes, addicts etc. I believe he killed the girls either at the hotel or nearby and began to dispose of them behind the hotel, because he realized he was able to hide them without being discovered. And being that sort of motel it is, people were unlikely to ask questions or even notice. After discovery of the bodies and ensuing media, I believe he evolved in the sense where he discovered outcall services on craigslist, and combined with using prepaid cell phones, he could severely limit his risks of exposure. He also probably found more confidence in being on his home turf, and this felt he could hide the bodies better than he did in AC. His evolution, combined with his confidence, gave him the sick idea of calling one vic's little sister and taunting her.
I believe he is NOT LE, but rather someone who fits in well in all forms of society, i.e. wealthy, blue collar etc.. He is probably single or divorced, but is active and known in the community. I suspect he makes a good living and has a good, steady career, but probably not one that is often remembered or noteworthy. This is his pleasure, something that is entirely his, and he feels empowered by it. Once he first committed the inital murder (whenever that was) he couldn't stop doing it. And eventually over time, he created his own sick game out of it, all for his own pleasure.
As people have posted earlier, I think the keys to finding him are:
1. The ID of the child found today, it is alot easier to ID and track a missing child than a prostitute. Why the change? Wrong place, wrong time, or something planned?
2. The burlap, hiding multiple bodies in burlap, requires either the purchase or aquiring burlap sacks from somewhere. where did they come from?
3. SG, perhaps the reason LE has not found her, is because she is the one who created all the witnesses, media, and led to the police. In recognizing SG created witnesses and was able to briefly escape and call 911, the SK wanted to make sure no one ever found her. He put her somewhere other than with the rest.
4. Police have been quoted as saying once he makes a mistake he will be caught. I believe he has already made that mistake, LE just need to connect it with the case. it will be something seen as previously miniscule, but will lead them to the SK.