He is often called "Auggie" by his partner Pat Mahon. He is generally regarded as a "hump", since he has not made a single case in property crimes over their last ten years. He is also an alcoholic.
After his partner Mahon retired due to injury, Polk considers deliberately injuring himself to follow in his partner's footsteps. Unable to follow through on his plan, he becomes despondent and goes on a drinking binge. He misses several days' work and finally shows up drunk at 9am. Lieutenant Daniels tells him to take sick leave for his alcohol problem or work "wet". Polk opted for sick leave and is off until the case is closed.
In the second season, he is briefly assigned to the first Sobotka detail under Lieutenant Grayson. When Major Valchek complains about the unit being full of humps, Daniels is put in command and Polk is moved back to property.
In the ninth episode of the fifth season, Polk makes a small cameo, as the officer running the evidence control locker in one of the precincts. After helping Commissioner Daniels locate a crucial piece of evidence, Daniels tells Polk that he's "glad he landed okay". Displaying his usual sarcasm, Polk replies "Yeah...beats working".
It is unclear whether the name of the pair, "Polk/Mahon", is intentionally homonymic with the Irish expression "póg mo thóin" (pronounced "pogue mahone") or "kiss my arse" in English, though it seems likely as these two not very good officers strolling through their working day waiting to hit police retirement age, being assigned to the detail is seen as an insult on the integrity of the detail, and the seriousness the chiefs higher up in the police force take the details' investigation.