There is no words for that
This seems to be a declarative sentence. It talks about the reaction of the policeman to a specific thing. His expression is not pleasant. What he might saw is something not good and something to worry about. Other possible thing could be there an heinous crime scene that he faced at that moment. It depends on the situation.<span />
Irony is definitely the answer to your question.
I think that the element of the story that is least related tot he author's biographical story is the C. SMELL OF MILDEW IN A VIETNAMESE VILLAGE.
Tim O'brien wrote the story using his personal experiences. He was sent to Vietnam in his tour of duty. He's familiar with the geography of the Vietnamese coastline, he vividly describes the climate and landscape, and he feels the fear that the soldier felt during wartime.
1. Illegal
2. Cheating
3. Stealing
4. Copying
5. Degrading