I also try to include a song where the woman murders her partner. (Monongahela Sal, Frankie And Albert, Leaving Home, Miss Otis Regrets)
I've noticed that the songs where the murderer is a man who murders his partner, he is portrayed as a scumbag and ends up hanging from a white oak tree or spending his life in prison. The song is also usually sung in the first person.
In the songs where the murderer is a woman, she is usually sympathetic and we feel that the murder victim deserved it. These are almost always sung in the third person.Then there are murder ballads where sex is not involved or at least the murderer and the victim are not involved romantically. "I shot a man in Reno, just to watch him die."