The answer to this question can be found in the second paragraph, which is after Captain Torres enters the barber's shop and sits down for a shave, demanding the barber's services. Note what the barber thinks:
I estimated he had a four-day beard. The four days taken up by the search for our troops. His face seemed reddened, burned by the sun.
As the story develops the reader understands that Captain Torres represents the miliary junta and the barber actually works for a rebel group of dissidents. The reference to "our troops" indicates that Captain Torres spent the last four days hunting down rebel troops, and, as the story makes clear, he caught some and will publicly torture them that very day. Tellez is very careful in this masterful short story to place the barber in a real dilemma, as he is the one person who has direct access to the throat of Captain Torres, and therefore needs to decide what he is going to do as a result.