SACRAMENTO, Calif. (AP/CBS13) — A man affiliated with the white supremacist Aryan Brotherhood prison gang pleaded guilty Monday to conspiring to distribute heroin and methamphetamine inside and outside California’s prisons, federal officials announced.

Samuel Keeton, 41, of Menifee, pleaded guilty to conspiracy to participate in a racketeering enterprise and to conspiracy to distribute heroin and methamphetamine, U.S. Attorney McGregor Scott said.

Keeton assisted the prison gang between March 2016 and at least October 2016 by picking up and distributing methamphetamine and heroin on behalf of the Aryan Brotherhood and delivering drug proceeds to their associates outside of prison.

According to the plea agreement, he also smuggled phones, drugs and other contraband into California State Prison Sacramento with the help of Southern California lawyer Kevin MacNamara.

READ: Leaders Of White Supremacist Prison Gang Aryan Brotherhood Charged In Killings

Keaton was one of 16 Aryan Brotherhood members and associates charged in June with directing killings and drug smuggling from within California’s most secure prisons by using contraband cellphones, encrypted chats, text messages, multimedia messages and email, prosecutors said.

They include nine current inmates charged with racketeering, conspiracy and other charges, and seven people outside prison accused of assisting the gang in activities in Las Vegas and as far east as Missouri and South Dakota.

Among the inmates charged is Daniel “Danny” Troxell, 66, a convicted killer serving a life sentence who was known for writing a federal complaint in 2009 that eventually led California to curb the use of solitary confinement.

The charges also allege that Ronald “Renegade” Yandell, 56, and William Sylvester, 51, used smuggled cellphones to direct heroin and methamphetamine trafficking operations in California from their shared cell at California State Prison Sacramentp.

Yandell, serving a life sentence for a double murder, is described as one of the gang’s three-member leadership, as is Troxell.

“As part of his guilty plea, Keeton admitted that he knew that Yandell and Sylvester were AB members based upon his discussions with them during 2016, including the crimes that he was asked to commit and that he agreed to commit, such as assisting in smuggling cellphones, drugs, and other contraband into prison,” prosecutors said.

Keeton is due back in court for sentencing on March 29, 2021. He faces a maximum penalty of life in prison and a fine up to $10 million.

More from CBS Sacramento: