Women are better are covering it up. I think men are more prone to acts of passion or random bouts of rage, which is difficult to plan for and cover up. It's often public, loud and messy. Women internalize from an early age that this is not acceptable behaviour if you're not male, so we reign it in more. But that doesn't mean the crimes aren't committed, we're just always cognizant of the social fallout if we're discovered.
Anyone who has worked in a retirement home can tell you there are some very sweet ladies who will, on or near their deathbed, tell you how they killed their abusive husband decades ago. Or they share the story like words of wisdom to the younger generation.
I think a lot of women have been put in a corner by society, so they don't feel a pressing need to play by the rules all the time.