Christopher Robertson, 42, of Fairburn, Ga., near Atlanta, appeared in the U.S. District Court for the Northern District of Georgia on Monday facing charges of threatening to kill Jews and black people.

“The allegations against Robertson, which include menacing visits to Jewish facilities and vile online threats against Jews and blacks, are of great concern,” stated Theodore Hertzberg, U.S. attorney for the Northern District of Georgia.

“Protecting the community from hate-fueled violence is a foundational part of the Department of Justice’s mission, and we will aggressively prosecute criminals who abuse the internet to terrorize and intimidate others,” Hertzberg said.

Paul Brown, special agent in charge of the FBI’s Atlanta office, stated that Robertson’s “alleged actions serve as a disturbing reminder of the terrifying hatred our Jewish communities encounter simply because of their beliefs.”

Robertson, who also goes by James Lomak, is accused of driving into the parking lot of the Jewish Federation of Greater Atlanta building without permission and trespassing. He told Federation security staff that as the “official spokesperson for the white race,” he wanted to speak to a senior Jewish official, the U.S. Department of Justice said.

After he was asked to leave, Robertson drove to The Temple, a Reform congregation in Atlanta, where he asked two staffers to speak to a rabbi. “Robertson made derogatory remarks about Jewish people and ranted about the decline of the white race,” the Justice Department said. “An Atlanta Police Department officer was present inside The Temple, and Robertson left.”

The FBI and the Secure Community Network—the security arm of the Jewish Federations of North America—found social media accounts that Robertson used that had “recent antisemitic and threatening video posts,” according to the Justice Department.

Those, included a YouTube post, in which he sang and directed expletives at Jews and said that “if you Jewish, one shot, two shot, leave you in the sewage,” and a July 28 Facebook post, in which he held a pistol and talked about “cultural genocide” of the white race and which contained the caption: “I will not tolerate cultural genocide get that understood—I will fight for it, I will die for it. I will kill for it.”

The Justice Department said that Atlanta police protection increased at about 80 Jewish sites in the city after the investigation of Robertson.

On July 31, the department alleges that Robertson posted on Facebook that he hoped to “chop it up with a rabbi.” He then went into a Chabad building in Peachtree City, Ga.

“The Chabad rabbi called 911 while members of the staff barricaded themselves in an office. Robertson recorded the encounter and posted it on Facebook,” the department said. “In the post, Robertson identified himself as the ‘official delegate of the white race’ and told the rabbi that Jewish people were on the ‘verge of extermination.’”

Robertson left the Chabad after police arrived. On Aug. 1, he posted a Facebook video in which he said he would kill black people, who “lash out openly at the white man.”

Later that day, Robertson barricaded himself in his home for “hours” as the FBI sought to arrest him. He eventually surrendered, after which agents found a gun on site, the Justice Department said.

The defendant is due in court again at 9:30 a.m. on Aug. 7.