Rio Grande Revenge by Chet Cunningham
In jail for cutting up a gringo in a fair fight, Juan Romero now rides with the outlaws! He's been with them since leaving his wife and young son behind in Mexico. On his return he finds them taken prisoner by a murderous officer of the Federales. They face certain torture and death-unless the Outlaws can submerge Batista and his thugs in a pool of their own blood.