Well, here's what happened:
A couple of months ago a stranger was running around town, trying to get invited in by the townsfolk just to bite them and drink their blood.
That did quite a number for the towns sense of security.
Some people didn't recover (RIP Grandma Maude), some moved away, the rest is extremely paranoid when it comes to strangers.
The local government has military personell roam the street during curfew in an effort to restore some sense of security.
Prepare to meet new faces who heard the mumblings in the neighborhood, and old faces that are extremely hard to fool now.