Rio Arriba County Sheriff Tommy Rodella and his son violated the civil rights of a man by tailgating him on Highway 399, blocking the man's vehicle with an unmarked Jeep, assaulting him with a silver revolver and later misrepresenting that the man attempted to injure the sheriff during the March 11 encounter, according to a federal grand jury indictment unsealed on Friday.

The five-count indictment charges the father-son duo with violating the man's civil rights and for making false entries in police reports about the incident.

Federal agents arrested Rodella, 52, and his son, Thomas Rodella Jr., 26. The two pleaded not guilty in federal magistrate court Friday.

US Attorney Damon Martinez couldn't elaborate on the motives for the alleged crimes. The indictment only names the victim by his initials, M.T.

The father and son pursued M.T. in the father's personal Jeep and challenged him to a fight, alleges the indictment. "In response to the victim's request to see his badge, Sheriff Rodella allegedly pulled the victim's head up by his hair and slammed his badge into the victim's face," according to the New Mexico US Attorney's Office.

The sheriff then instructed his deputies to arrest the victim, according to charges, and detain him at the Rio Arriba County Detention Center. The feds charge the two with falsely misrepresenting on arrest reports that the man attempted to injure the sheriff.

The US Attorney's Office 

with the statutory maximum prison sentence for the charges, each man could face up to 30 years in federal prison.