During the 1970s into the 1980s, Kenneth Rex McElroy allegedly bullied basically the entire town of Skidmore, Missouri. One day, he was finally convicted after shooting the owner of the town's general store. However, while out on bond pending an appeal in that conviction, the town took matters into their own hands.
Sources for this episode:
Wikipedia - Skidmore, Missouri
Wikipedia - Ken McElroy
The Killer Book of True Crime by Tom and Michael Philbin
BuzzFeed - 18 Facts About The Murder of Ken Rex McElroy, One Of The Most Interesting Moral Dilemmas Ever
Fox2Now - Bully's murder remains a secret in Missouri town for 40 years
All That's Interesting - The Story of Ken McElroy - The Vicious Bully Killed by His Town
No One Saw A Thing