Mothers killing their own children is shockingly more common than you think, so much so that there's even a term for the killer moms who do it — filicide. Although people might wonder in confusion as to how a parent can take away the life of the one thing they are supposed to love and protect, psychologists say there are several reasons for why moms choose to kill, from spousal revenge to altruistic motives. But the main thing that ties all these cases together, regardless of the motive, is mental health.

"Mothers with very young children are infinitely more vulnerable when a partner deserts them and walks out on them," filicide expert Kieran O'Hagan said. "This can lead to them developing mental illness and within that condition, they reason there isn't any way out for them. They come to the conclusion that they have had enough and they want to take their own life and it's inconceivable to them that they take their own life and leave their children."

From famous mom killers like Andrea Yates to recent ones like Christy Sheats, here's a look at 11 shocking crimes that still leave us speechless.