The mass shooting in and around the Tops grocery store in Buffalo, New York on May 14, 2022 that claimed the lives of ten individuals and injured three others was all the more horrific because of the white supremacist ideological motivation that fueled it and the shooter’s meticulous planning. The disturbing reality is that this attack is part of an epidemic of mass shootings often perpetrated by young men radicalized online by an ideology of hate. This report details what my office has learned about how the Buffalo shooter was first indoctrinated and radicalized through online platforms, and how he used these and other platforms to plan, implement, and promote these acts of terror. The report assesses the strengths and weaknesses of the response of various online platforms in the wake of the Buffalo shooting. Readers should be cautioned that this report contains graphic textual descriptions of bigotry and violence, including quotes from the shooter’s own writing that, in our opinion, are necessary to contextualize and explain this story.