Sexist Shooters

He began his attack by entering a classroom at the university, where he separated the male and female students. After claiming that he was "fighting feminism" and calling the women "a bunch of feminists," he shot all nine women in the room, killing six. He then moved through corridors, the cafeteria, and another classroom, specifically targeting women to shoot. Overall, he killed fourteen women and injured ten other women and four men in just under twenty minutes before turning the gun on himself. (1989)

He ordered the hostages to line up against the chalkboard and released the 15 male students present, along with a pregnant woman and three parents with infants. The remaining 10 female students he kept inside the schoolhouse. […] The gunman apparently killed himself along with five school girls. Three of the girls died at the scene, with two more dying the next morning from related injuries. Five girls were in the hospital in critical condition. Reports have stated that the girls were shot execution style in the head. The ages of the victims ranged from 6 to 13. (2006)

The shooting occurred at a women's aerobics class at the LA Fitness center in The Great Southern Shopping Center of Collier Township at approximately 8:15 pm EDT. The shooter entered the class, placed a duffel bag on the ground, turned off the lights, took out two handguns and began firing […] Three women and the gunman died, and about nine other people were injured. (2009)

Ed. the case of Arunya Rouch (heard of her?) makes me think there might be more cases of women attempting the reverse, they just don't get much attention. Amy Bishop is a conspicuous example, along with Aileen Wournos. Some Googling turns up Laurie Dann, Jennifer San Marco, Brenda Spencer, and Sylvia Seegrist. It's all nonsense, of course. Like hutu and tutsi, the difference between males and females (above the shoulders, anyway) is fiction.
Ed. how could I forget Julie Schenecker? We must specialize in this stuff in the bay area. To whit: all our female teacher sex scandals, Debra Lafave et al.