The Bloody Benders

The Bender family, more well known as the Bloody Benders, were a family of serial killers in Labette County, Kansas, from May 1871 to December 1872. The family consisted of John Bender, his wife Elvira, their son John Jr., and their daughter Kate. 

While there is no definitive number, estimates report that the Benders killed as many as twenty people before their crimes were even discovered. The family's fate remains mystery as well, with theories ranging from their deaths at the hand of justice to a successful escape. Much folklore and legend surround the Benders, making it difficult to separate fact from fiction.

Trigger warning for explicit content.

https://en.wikipedia.org/wiki/Bloody_Benders