Authorities have arrested and charged an Indiana man for threatening Rep. Joe Donnelly and his staff.

According to a complaint filed in a U.S. District Court in Indiana, Brett Keiling, 46, called the Indiana Democrat’s South Bend office Monday around 9:30 a.m. and threatened a staff member.

Keiling allegedly accused Donnelly’s office of “back-stabbing him” but failed to convey what specifically he was upset about. 

“I am going to come and back-stab you,” Keiling allegedly told a Donnelly staffer. “I mean literally come down and stab you.”

The staffer phoned the FBI office in South Bend, and authorities arrested Keiling on Monday evening at his home.

Keiling, who calls Donnelly’s office regularly to discuss current events and media highlights, reportedly phoned three additional times that day, the latter without threats. He also has a reputation for calling the local FBI office once or twice a week, according to the initial court complaint. 

“We’ve had numerous issues and dealings with him over the years,” said Sgt. Bill Redman, spokesperson for the St. Joseph County Police Department. 

Redman said the department has arrested Keiling 23 times on charges including intimidation, stalking, harassment and marijuana possession. He’s been admitted at least twice to the Indiana Department of Corrections.

Keiling is being held in the county jail without bond and is scheduled to appear in court for a preliminary hearing Monday.