Nearly two years after the shooting , police opened an investigation into Sonboly 's contact with William Atchison , perpetrator of the 2017 Aztec High School shooting , and with a boy in Gerlingen who planned a school shooting there . Shortly after the Munich shooting , Atchison wrote an epitaph to Sonboly on Encyclopedia Dramatica , calling him a " true Aryan " and " true German "
Aztec High School shooting
Aztec High School shooting
2016 Munich shooting