Lpez Rivera was first linked to the criminal conspiracy carried out by the FALN in 1976. That year, a burglar was arrested in Chicago attempting to peddle stolen explosives. The burglar led the Chicago police to an apartment, nearly void of furniture, but in which there were boxes containing explosives and bomb-making paraphernalia, weapons, clothing, wigs, and photographs of Chicago buildings, maps of the city, and several FALN documents, including a manual for guerrilla.
He was charge with seditious conspiracy,use of force to commit robbery, interstate transportation of firearms and ammunition to aid in the commission of a felony.
In 1988 he was sentenced to an additional 15 years in prison for conspiring to escape from from the Leavenworth federal prison.