The Long Island Serial Killer has been at large for 20 years. He's killed at 10 people, the bulk being sex workers, and left their bodies in the Gilgo Beach area. Who is this mysterious killer? Or are their multiple killers working together? Why did the police exclude so many suspects so early on in this case? We attempt to unravel this mystery in this week's episode of Killin Missin Hidden!https://en.wikipedia.org/wiki/Long_Island_serial_killerhttps://abcnews.go.com/U...