A former prison officer was convicted Tuesday on charges of aiding a white supremacist inmate gang that operated at the California Institute for Men in Chino. Shayne Allyn Ziska, 44, of Fontana was found guilty of federal charges of participating in a corrupt organization's conspiracy, violent crime in the aid of racketeering and deprivation of rights under color of law.

Ziska helped the Nazi Low Riders distribute methamphetamine, heroin and other drugs, federal prosecutor Adam D. Kamenstein said. U.S. District Judge Terry J. Hatter Jr., who heard testimony from several inmates and other correctional officers over a two-week trial, also found Ziska guilty of allowing a gang member to stab an inmate. Ziska faces up to 50 years in federal prison when he is sentenced May 8.

The Nazi Low Riders emerged in the 1970s in the California Youth Authority before spreading throughout the adult system and beyond the prison walls. The gang has gained strength with the arrest and successful prosecution of top members of the Aryan Brotherhood, a larger, more established prison gang. Federal authorities claim the NLR now controls much of the illegal activities of white inmates in California prisons.

Ziska was placed on administrative leave from the prison in 2000 because of a California Department of Corrections investigation that was later turned over to the FBI. Kamenstein declined to say what prompted the probe.