hedwards: The ones that are caught are overwhelmingly male. Women tend to engage in things like "mercy killings" via subtle medical mistake and other methods that are less likely to lead anybody to suspect that there's a serial killer on the loose.
Coelocanth: Serial killers are overwhelmingly and predominantly male. I didn't say there weren't female serial killers. There most certainly are. But if you're suggesting there are as many female serial killers as male, and it's just that they haven't been caught, that's beyond ridiculous.
You do realize that it would be easy to overlook an epidemic of female serial killers, right? There's a small handful of them every decade and one could easily overlook that many nurses with patients that have a markedly lower life expectancy.
What's more murders that are committed by women don't always look like the ones committed by men. Sometimes they are, but often times they're not and it's really not that hard to believe that it could go unnoticed enough times to bring parity to the situation.
Certainly easier than ignoring the half of domestic violence that's perpetrated by women.
And yes, society is that screwed up and sexist that it's hardly implausible.