The policeman who arrests Jurgis after his fight with the bartender is the one who takes him in front of the Judge who sentences him for 10 days for his conduct. In a larger sense, the police officers that Jurgis encounters represent the corruption that makes it impossible for people like Jurgis to live out "the American Dream." In the novel, the police officers are shown to be little more than functionaries of the larger system of corruption and graft that advances life in Packingtown and in other American urban centers at the turn of the century. The police officers accept bribes from businessmen, politicians, and factory owners. They are essentially rented out by the establishment who use the police as their own security force. At the same time, the underworld figures of criminal activity interact with the police through bribes and corruption also to advance their own agenda. Jurgis discovers this when he turns to a life of crime and fully grasps this condition when he moves towards embracing Socialism at the end of the novel.
The inclusion of the police officers in the narrative helps to highlight Sinclair's point that capitalism has made it impossible for the poor to ever get a level playing field. If the poor realize how corrupt the system is, their only refuge is the police. Yet, it becomes clear that the police are not interested in seeing how they can help the poor. Rather, the police seeks to silence them. Jurgis has a reasonable claim against being cheated by the bar owner. Yet, the police officer who intervenes bops him on the head with his night stick and takes him off to be sentenced in front of the judge. Jurgis is afforded little in way of due process, institutional understanding, or the force of advocacy that the police should be in any setting. Rather, Sinclair has the policeman operate as a force of silencing dissent, ensuring that the capitalist system is not interrupted and not disrupted in using human beings as part of the grist of its machinery. In The Jungle, this becomes the role of the police man and the police, in general.