The Officer in the story is neither the good guy or bad guy. He may be doing inhumane things such as torturing prisoners, but he honestly believes he is doing the right thing. We see this in many instances when he is explaining the apparatus to the traveler: “The basic principle I use for my decisions is this: Guilt is always beyond a doubt.” (Kafka 4) He does not give the accused a chance to defend themselves because he does not believe that is the right thing to do. From his experience in working with the Old Commandant, he has learned that the accused will always lie. We see this in the text when the Officer says: “He would have lied, and if I had been successful in refuting his lies, he would have replaced them with new lies, and so forth.” (Kafka 5) Simply put, he sees this as the proper way to judge the accused and in a sense he is reflecting a statement of truth. If humans are accused of something, they will often try to lie their way out of it due to fear. This is typical human nature.
Also, the Officer, unlike everyone else, has stuck to what the Old Commandant has taught him. Since he worked so closely with the Old Commandant it was probably very difficult for him to turn away from the morals that had been instilled in him for so long. The Machine and punishing the Condemned seems like the normal and proper thing to do in the Officer’s mind. Therefore, you cannot really say he is a bad man. He is doing terrible things with the best of intentions, and intentions say a lot about a person. Therefore since he is neither the bad guy or the good guy, but simply a man led astray by a bad leader.