The Los Angeles Police Department (LAPD) is the police department of the city of Los Angeles, California. It is the third-largest municipal police department in the United States, after the New York City Police Department and the Chicago Police Department. The LAPD is part of the larger Los Angeles Police Department, which is responsible for providing law enforcement services to the entire county of Los Angeles. The LAPD is responsible for patrolling the city of Los Angeles and responding to calls for service. The LAPD also investigates crimes, apprehends suspects, and enforces laws.