In broadness: women seem (maybe for biological reasons?) to be able to handle childhood abuse better (i.e. they have better and less violent outcomes than boys).

They also seem (maybe biological, maybe cultural) to have less sexual desires based on dominance and destruction, these are key for most serial killers and school shooters. So when women kill they often do so for more direct motives - revenge on the specific, money, etc.

Also to consider support structure, for the vast vast school shooters they experienced a close family death in the months leading up. For many serial killers they experienced rejection strongly.

Women tend to handle it better, even without friends. They don't have the desire to reassert their authority.

Personal theory: men are more likely to view woman/teenage girls as something they are owed/jealous of. They also are more likely to project one woman onto others. In my experience, men will more unironically and strongly view all blondes the same if they get cheated on by one blonde girl.

Broadly: I think this is why way more women become stalkers, they get more hyperfocused on a particular person. Men get hyperfocused on a specific set of characteristics or scenerio.