Marybeth Tinning was born in 1942 in New York and had an average childhood. She married in 1965 and had two children with her husband, but then her father died and their third child died of meningitis. Over the next 14 years, all nine of her children died, including an adopted son. She was eventually convicted of killing her final child and sentenced to 20 years in jail. Tinning exhibited behaviors consistent with Munchausen Syndrome by Proxy, a psychological disorder where one seeks attention by harming another person under their care.