According to the article, this psycho is a biological male who purports to be female. He probably decided to "be" female because he couldn't cut it in his school's men's athletic programs. Then, when he probably couldn't even make the cut in his school's women's athletic programs, he decided to shoot up the school. Who knows? They just need to put him in a rubber room.
The essential American soul is hard, isolate, stoic, and a killer. It has never yet melted. ~ D.H. Lawrence