Many recent mass shootings share a troubling connection: The accused killers have left a blueprint for their alleged actions on social media, like the attack on a Pittsburgh synagogue last year in which 11 people were killed, and the massacre in Christchurch, New Zealand in which 51 were killed.
The alleged gunman in El Paso, Texas posted his manifesto to the online message board 8chan minutes before the shooting. Cloudflare, the network provider for 8chan, has since announced it is dropping the site. But the El Paso suspect was not the first to use 8chan; other mass shooting suspects have done the same.
“You have would-be recruiters and provokers who are using these platforms to get to people on a personal level,” said Nate Snyder, a former counter-terrorism official in the Department of Homeland Security.
The online posts are out in the open, but difficult for law enforcement to spot unless they get a tip before an attack happens.