At the beginning of the Cuban Revolution, Aruca became involved with the Movimiento Revolucionario del Pueblo (MRP), an organization led by Manuel Ray, an architect who had served as Fidel Castro's minister of public works. Aruca was the propaganda director of the student wing, and distributed anti-revolutionary leaflets and to organize strikes. He was arrested on January 5, 1961, and charged with counterrevolutionary activities, tried ten days later, found guilty, and sentenced to 30 years. Aruca was sent to Havana's La Cabana prison.