Sgt. Sam Hall of Company F, 4th AZ Brigade. He and several others in the company deserted to Mexico in late March 1864. He later wrote for the storypapers and dime novels detailing some of his experiences as a Texas Ranger before the war and then as a soldier.
I'm also looking to track down info on "Lev Sutherland" and a "Col. Wilson" that Sam says brought 300 men from Calif. and Arizona (i.e. "Wilson's Brigade") to fight with the 4th AZ and was in charge of the unit the night he deserted. My hunch is that this was "Capt. T. A. Wilson" of Company A who had been part of the Showalter Party in 1861, but I can't confirm.