In court Monday, Daniel Barefoot said he understood the charges against him and asked for a court-appointed attorney.
On Friday, deputies found two pipe bombs and bomb-making materials at Daniel Barefoot's home on Christmas Tree Road near Dunn.
Authorities also searched the home of his father, Charles Barefoot, on Mamie Road near Benson. Investigators seized a number of assorted weapons. Confederate flags and Ku Klux Klan robes were also found, according to Sheriff Steve Bizzell.
Authorities said Charles Barefoot was Grand Dragon of Nation's Knights after breaking away from the National Knights.
Authorities said Charles Barefoot may have been responsible for threats to blow up the Johnston County Sheriff's Office, the sheriff, the county jail and courthouse.
Authorities said as many as 12 people may have attended Barefoot's meetings, but they have not seen an increase in activity from hate groups.
"We don't have any indication that we have a problem. Hopefully, this is an isolated incident," said Dale Wheeler, a detective with the Johnston County Sheriff's Office.
Charles Robert Barefoot is being held in a federal facility in Wilmington. He is scheduled to appear in federal court Wednesday.