A police complaint, also known as a First Information Report (FIR) in some jurisdictions, is a formal written document filed by a person or entity with the police to report an alleged criminal offense or unlawful incident. It serves as the first step in initiating a criminal investigation. The complaint must contain specific details about the incident, including the date, time, location, and names of individuals involved, if known. Upon receiving the complaint, the police initiate an investigation based on the information provided. Police complaints are essential for enforcing the law, ensuring public safety, and upholding justice.