The gruesome true story of a murderous modern-day Medea. In June of 1985, Theresa Cross Knorr, with the help of her teenage sons, dumped the body of her daughter Sheila in California's desolate High Sierra. Knorr had beaten Sheila unconscious 3 days earlier, then locked her in a closet to die. This unbelievable yet true tale of a monstrous, abusive mother murdering not 1 but 2 of her children is almost too horrific to describe. The previous summer, in an attempt to erase evidence that she had shot Sheila's sister Suesan, Knorr had dug the bullet out of the girl's back with a paring knife. Deprived of proper medical care, Suesan had quickly developed a severe infection, prompting Knorr and her 2 sons to drive the delirious child into the mountains where they doused her with gasoline and set her on fire. Knorr got away with both murders for nearly 9 years, until her youngest daughter, Terry Knorr Graves, revealed the dark secret of her mother's unfathomable actions to the police. How could a parent so callously kill her own kids? Mother's Day depicts the shocking life of a woman whose violence, jealousy, rage, and domination led to brutally heinous crimes of ruthless ferocity.