Scott Vicente Hernandez, 42, of Oakland, Calif., was being held in the Ada County Jail on drug charges when he assaulted a corrections deputy on Oct. 16, 2013.
Hernandez was one of 11 suspects indicted last summer on federal charges of conspiracy to distribute methamphetamine in Canyon County.
The defendant pleaded guilty Tuesday to the assault charge and in December on the drug count. He will be sentenced on both charges on Sept. 9.
Hernandez faces five to 20 years in prison on the conspiracy charge and up to one year on the assault charge.
All 11 of the drug ring defendants pleaded guilty.
Those who were sentenced earlier include: Nearia Pinnell, nearly three years; Juan Luis Mojica-Barragan, nearly five years; Daniel Vaughan, about six and a half years; Wendy Harrison, Bobbi Eileen Woolsey and Carlos Eberardo Tovar, seven years each; Michelle Ritch, 10 years; Darrell Zirschky, 14 years; and Jeramie Ethan Mahler, 20 years.
The 11th defendant, Hernan Gomez Gutierrez, will be sentenced July 1.
The case was investigated by the Treasure Valley Metro Violent Crimes Task Force, which is comprised of numerous federal, state and local agencies. Prosecutions are handled by the special assistant U.S. attorney hired by the Treasure Valley Partnership and the state to address gang crimes.