(Newser) – The FBI has arrested a white man in his mid-20s who allegedly threatened to kill black students at Howard University two years ago, and the investigation involved a nifty bit of internet sleuthing. Agents first traced the threat posted on Reddit and 4chan to the wireless internet at a Panera Bread in Alexandria, Va., reports KSDK. Then they looked at who was on the network that day in 2015 at Panera and discovered that John Edgar Rust was among those who had connected, per the Washington Post. This was already strike one against Rust, who wasn't supposed to be on the internet at all thanks to a 2012 conviction for aggravated sexual battery and "indecent liberties with a child by a custodian."

Agents searched Rust's computer and found that he'd visited both Reddit and 4chan around the time the threats were posted. They also found text of the posted threat, which read in part, "Any n-----s left at Howard University after 10 tomorrow will be the first to go," he wrote. "After all, it's not murder if they're black." The threat also referred to race protests at the University of Missouri, and agents found searches on Rust's computer about that. Authorities arrested Rust on Wednesday, and he faces up to five years in prison over the threat. "Relieved," read a tweet from Howard University upon news of the arrest. (Read more racism stories.)

