In this episode Justine introduces Damon to a woman who was a serial killer with 14 confirmed kills and a very mysterious death.

Sources:

https://laportecountyhistory.org/exhibits/belle-gunness/

https://allthatsinteresting.com/belle-gunness

https://murderpedia.org/female.G/g/gunness-belle.htm

https://www.legendsofamerica.com/belle-gunness/

https://www.syfy.com/syfy-wire/triflers-need-not-apply-the-story-of-deadly-belle-gunness