Given the following context:  The movie opens with shots from the Spanish Civil War, and a line of Spanish refugees crossing the border into France after defeat by the Francoists. Republican guerrilla fighter Manuel Artiguez turns away from the border and back towards Spain. His friends stop him, saying "Manuel, the war is over!". The story returns twenty years later, to a young boy named Paco, who asks a man named Pedro why Artiguez, who is legendary for his fierce resistance to Franco even after the defeat of the Republicans, has stopped his guerrilla raids against the Francoists in Spain. Pedro sends Paco into France to find his uncle and Artiguez. Paco tells Artiguez that he wants him to kill Viñolas, a Guardia Civil officer, for killing his father. Paco lets Artiguez know that his father was killed because he wouldn't tell the police where to find Artiguez, whom Viñolas must capture if he is to retain his rank in the Guard.  Meanwhile, Viñolas has learned that Artiguez's mother is dying, and sets a trap at the hospital in San Martín to capture Artiguez, presuming that he will come to see his mother. Like all Republican sympathizers, she is contemptuous and deeply suspicious of all Catholic clergy, who collaborated with the fascist Franco regime, both during and after the war. In return for information about the layout of the hospital and surrounding area, Paco tells Artiguez to "bump into Viñolas" for him.  answer the following question:  Whose father did Viñolas kill?
Paco