Community·Posted on Jul 12, 2017What Fact About Serial Killers Freaks You Out The Most?What. The. Fuck.by Anna KopskyBuzzFeed StaffFacebookPinterestTwitterMailLink Serial killers are terrifying enough as it is, but some have even darker facts about them that send chills down your spine. Lionsgate Maybe you've heard that the BTK Killer once worked as a home security system installer, which could be how he got access to many of his victims' houses. CBS / Via youtube.com Perhaps you're aware that John Wayne Gacy worked at a mortuary in Las Vegas in his youth, long before committing any of his crimes. Wikipedia Commons / Fair Use Or that The Vampire Killer of Sacramento said he mostly chose his victims based on whatever doors were unlocked when he walked down the street. Wikipedia Commons / Fair Use It's terrifying, yet so interesting, to learn about serial killers, so tell us: What's the creepiest fact you know about them? New Line Cinema Fill us with knowledge via the Dropbox below for a chance to be featured in an upcoming BuzzFeed Community post or video.