The indictment has three counts, two under the Ku Klux or Enforcement Acts from during Reconstruction, and one for using or carrying a firearm during “any crime of violence or drug trafficking crime.
The Ku Klux act charges are the heart of the prosecution. The first is under 18 U.S.C. 241, which comes form the Enforcement Act of 1870, one of three acts collectively known as the “Ku Klux acts,” which were designed to protect the rights of blacks to vote, hold office, serve on juries, and receive equal protection. It’s a conspiracy-based crime, making it a crime to conspire “to injure, oppress, threaten, or intimidate any person… in the free exercise or enjoyment of any right or privilege secured to him by the Constitution…”
The second count is under 18 U.S.C. 242, which comes from the Enforcement Act of 1871, and is the criminal law analog to 42 USC §1983, the act that makes possible civil lawsuits enforcing federal civil rights. It makes it a crime to “under color of” state law to “willfully subject any person… to the deprivation of any rights, privileges, or immunities secured or protected by the Constitution…”
Count three is the gun charge under 18 USC 924(c). They are accused of using and carrying the firearm during the crime. The punishment would escalate if they “brandished” (as opposed to just carrying) the firearm during the crime.