I also wonder if perhaps the person responsible for the 2006 murders, and possibly others, acted out on some beef he had with Atlantic County, NJ that somehow triggered that killing spree. Perhaps it was an an arrest, a foreclosure or loss of a job that set him off. It's a shame, actually, because AC is such a great place to have fun.
As always, just my opinion.
I would also by far put the greater likelihood of the murders being done to fuel someones sick sexual fascination. Although few of these cases match the prolific nature shown here, an average of one killing every nine days, it's almost always how these cases turn out to be. But I've had alternative theories floating around in my head such as the one you brought up here, like a beef with some entity associated with the area where they were found. Whatever the motive a couple things I think the killer almost had to know after the first victim. He was not going to stop at just one and it would not be long before they started finding the bodies.