Hmm...the family that slays together, stays together.
LOL! “Til death do us part (in jail)”
Then there's the Karla Homolka story. She set up her younger sister, among a couple of others, to be raped and murdered by her hubby.
She plead out against her husband, and got a relatively "short" sentence, that is, she's out with the majority of her life ahead of her.