>if a woman can drown her kids in a bathtub

I should note that Andrea Yates, the case you're thinking of, is... a way, way, way fucking weirder and sadder case than pop culture has largely determined it to be.

She was suffering from unmedicated bipolar 1 that wasn't taken seriously by... more or less anyone around her, and while her husband was away on a business trip, she fell into a manic episode that caused the delusion that her kids were possessed by demons and that God was going to damn her to Hell if she didn't kill them.

She's one of the very, very few high-profile murderers in... the entire recent history of the first world, really, to successfully use an insanity plea, and will likely spend the rest of her life in a mental institution, and that is in no way a miscarriage of justice.

This isn't really relevant to Gone Girl, I'm just bringing all of this up because that case happened relatively locally to me and pop culture's mutation of it is a little bit of a sore point for me.