Here is Shannon's missing person thread:
http://www.websleuths.com/forums/showthread.php?t=122841&highlight=Shannon+Gilbert
I go back and forth about whether I think SG is connected.
I can see coincidence being at work here. If the killer does live or rent in Oak Beach (I still think he's a summer person, not a permanent resident), then her stumbling into him is no longer such a wild coincidence. Coincidence, yes, but he's gotta live somewhere, and people wherever that is are going to have contact with him.
The other thing is if somehow this guy is tracking vulnerable women. I haven't worked out how that could happen -- in this case he might have been listening to the police scanners, or just attracted to the lights and fuss. If the women are traveling by LIRR, maybe he works for or travels on the railroad and has picked them out well ahead of time.