A member of a gang prominent in Idaho prisons faces up to 10 years in prison after pleading guilty to possessing an unregistered firearm.

Joshua Michael Trent, 31, is among 21 people charged in a federal investigation into the Aryan Knights, a gang said to be responsible for the distribution of methamphetamine in Idaho.

A grand jury indicted Trent in August in connection with the black-market sale of two sawed-off shotguns on May 7 in a Boise park.

Trent and co-defendant Christina Shantell Massie, 35, arranged to sell the guns for $600 to a man who turned out to be an undercover FBI informant.

Massie is scheduled to begin trial on Dec. 3.

Trent is to be sentenced Feb. 5 by U.S. District Judge Lynn Winmill in Boise.

Reputed Aryan Knights members James Everette Hood, 40, and Rory Vincent Palma, 38, pleaded guilty last month to being a felon in possession of a firearm. They face up to 10 years in prison when they're sentenced Feb. 11 by U.S. District Judge Edward Lodge in Boise. A plea agreement detailing their cases has been sealed.

According to the U.S. Attorney's Office, 13 of the 21 people indicted face drug charges, including four counts of conspiracy to distribute methamphetamine, 15 counts of distributing methamphetamine, and four counts of possessing methamphetamine with the intent to distribute. Eight were indicted on firearm charges, including six counts of unlawfully possessing firearms, two counts of possessing sawed-off shotguns, and one count of transferring a sawed-off shotgun. Two were indicted on both drug and firearms charges, including two counts of distributing methamphetamine and two counts of unlawfully possessing firearms.

Those charged include Andrew Gallegos, 23, Jose Silva, 30, Shannon L. Stewart, 41, and Michael P. Duschka, 36, all of Boise. Thirteen were indicted on September 12, including Dallas Tyler Thompson, 31, Cameron James Ball, 25, Joshua Michael Nall, 31, Nicholas Andrew Steele, 26, Lisa Rochel Samayoa, 45, Jesse Ray Delgado, 47, Stephanie Ann Robinson, 29, and Dennis Lynn James, 45, all of Boise; Christopher John Solders, 26, and Darin Scott Melton, 44, both of Twin Falls, Idaho; Nina Ann Lucas, 32, of Pocatello, Idaho; and Mexican nationals Rigoberto Bastrana Carrasco, 36, of Ogden, Utah, and Omar Riveroll-Hernandez, 32, of Long Beach, Calif.