Marcus Wesson grew up in a tumultuous home. His religious mother left an imprint that was visible throughout his life. Marcus had a fascination for young girls, marrying a 15 year old in his late 20's. He believed himself to be a vampire and his clan could only grow through his insemination of his own daughters and nieces. He refused to work, yet wanted to reign over his family. When two of his daughters bring in authorities in a bid to get their children, Marcus puts a plan in motion. A plan that he had been grooming his most devoted child to complete. The murder-suicide resulted in the death of nine of his bloodline. Marcus believed there could be no proof of his actions if there were none left to talk. But Marcus didn't understand the proof in DNA and the DNA would ensure he would face justice.

Sources:

Veysey, N.; Decker, R. 2020. Marcus Wesson. The horrific true story behind Fresno’s worst mass murderer

https://www.investigationdiscovery.com/crimefeed/murder/marcus-wesson-believed-jesus-was-a-vampire-married-6-of-his-daughters-murdered-9-of-his-kids

https://abc30.com/marcus-wesson-mass-murder-children-killed-convicted-murderer/14518182/

https://www.fresno.courts.ca.gov/system/files?file=5-12-04-motion-dismiss-counts.pdf

https://abcnews.go.com/Primetime/photos/family-secrets-marcus-wesson-story-11076409

https://www.crimelibrary.org/notorious_murders/family/marcus_wesson/2.html

Deadliest Mums & Dads, Season 2, Ep 1: A Family Massacre