Looking back throughout history, we are hard pressed to find mass killings, especially using guns(usually automatic weapons) carried out by women.(If one researched it, maybe some members of a cult or political group included some women members) This has changed slightly, recently, only because a number of these mentally defective persons, as almost all mass killers are, were so called women (guys who identified as women). Bottom line if you are a mentally defective mass murderer you are most likely a guy, or were originally. Identify, however you want, but the testosterone says otherwise. https://www.zerohedge.com/markets/five-killed-mass-shooting-southwest-philadelphia-monday