The NYPD are responsible for enforcing the laws of the city and catching criminals posing a threat on the streets! They will respond to your :999 calls if you are in trouble and require assistance.
The New York Police Department is operated on a day to day basis by a player Chief, you can view the full Police Force on https://peakrp.com/corporation/1
You can apply to join the Metropolitan Police on the website: https://police.peakrp.com
You can submit a complaint about an officer on the forums: https://forums.peakrp.com/forums/nypd-complaints.9/