How to Respond to the Realization that Your Neighbor May, in Fact, Be a Serial Killer (Formerly Known as a 'Mass Murderer')

So.
You've done your research. You've read the signs. You've figured out that your neighbor shows Serial Killer or Serial-Killer-Like Tendencies! Knowing how vital it is for you to proceed with caution, I have put together this little post in order--I hope--to help prolong your life.
Incidentally, even if you haven't come to suspect that your neighbor may be a serial killer, it's probably in your best interest to take these tips to heart anyway. Because sometimes serial killers blend in. S...