I don't think I've ever heard of a woman committing aggressive, violent, mass murder.
Again, it's just not hard wired into them. This doesn't make them any less of a monster than a man that goes bad. It's just the way we are made. A woman is a knife, or a drop of poison when she goes crazy. A man is a bomb.
Can we get past the gender thing? It's nauseatingly obvious why men are capable of dishing more physical harm on others at this point.