We are given the answer to this question as the narrator begins too apply the lather to his face. The narrator comments that he had never been so close to Captain Torres before in his life. The only other time that he had come face to face with him was during what Captain Torres defines as his "fine show," when he had caught, punished and executed some of the rebels that the narrator supports for the "pleasure" and "enjoyment" of the whole town:
The day he ordered the whole town to file into the patio of the school to see the four rebels hanging there, I came face to face with him for an instant. But the sight of the mutilated bodies kept me from noticing the face of the man who had directed it all, the face I was now about to take into my hands.
Thus at the time the shock and the horror of what Captain Torres had done to the rebels prevented the narrator from studying closely his face - something that he now has ample opportunity to do.