Police: Alexandria man threatened to murder African-American students at Howard University

An Alexandria man was arrested nearly two years after authorities said he threatened in an online post to murder African-American students at Howard University.

John Edgar Rust, 24, was a convicted sex offender on probation at the time the threats were made, according to officials.

According to court documents, Rust posted on the website 4chan.com while he was at a Panera Bread in Alexandria on Nov. 11, 2015.

FBI agents said Rust was upset with racial tensions that were taking place at the University of Missouri at the time. Authorities said Rust used racial slurs repeatedly in his post and "promised" to kill black people at Howard University.

"Sure, the po po will take me down, but I'll go out a hero knowing I made the world a better place," Rust allegedly wrote in part.

Shortly after the post, Rust's roommate mentioned the threats on Reddit, saying, "Just consider yourselves warned," according to court document.

Within days of the threats, federal investigators said they were quickly able to trace the posts to the WiFi at the Panera Bread and then to Rust's laptop.

Forensics teams have worked since then to make the FBI's case, according to officials. Rust will appear in court for his arraignment on Thursday and if convicted he could face up to five years in prison.

Howard University said it was made aware of Rust's arrest and tweeted Wednesday evening that it was relieved the FBI had him in custody.