It absolutely does and a considerable number of officers will commit suicide, turn into monsters themselves, or otherwise wind up damaged as a result of years taking so many risks and being in that much danger. They see humanity at their lowest-- ranging from all the things you'd expect in the hood to domestic incidents in people who would appear normal to the rest of the world. They get to see the gruesome ways organized crime makes an example out of someone who crossed them. When there's been a big traffic accident, they have to go be there. They get to see and smell the aftermath of murder and death, and to a lesser extent witness how it affects the people related to these incidents.
Although the job may be less deadly while the soldier eventually gets to go home, the police officer is home. Over the course of a long career of this nature what might be changing psychologically?