mass shootings in the us happen because they are engineered by jews. look at the bully culture. its actively encouraged in the us by kikes who exploit the amerinigger brains obsessiveness with manliness(ameriniggers are not too different from balkanniggers in this regard). they promote bullying as a good thing and reward bullies. at the same time they penalize anyone who tries to fight back against bullies. it even got as far in one case as a disabled person getting penalized because he secretly recorded some classmate bullying him. the shool claimed recording was illegal and the disabled victim was the one who got punished which is fucked up as all hell. but again, i dont think these are applicable in this teen girl shooting case. its usually guys who shoot up schools because we have it the worst universally. just look up suicide rate for proof of that. so a girl shooting is an extreme rarity because they usually live on easy mode. so her life must have been really fucked up, which is why i think shes most likely a rape victim.
White Supremacist