William Joseph Bratton, CBE is an American businessman and former law enforcement officer who served two non-consecutive tenures as the New York City Police Commissioner and currently one of only two NYPD commissioners to do so.  He previously served as the Commissioner of the Boston Police Department (BPD) (1993–1994) and Chief of the Los Angeles Police Department (LAPD) (2002–2009). He is the only person to have led the police departments of the United States' two largest cities – New York and Los Angeles.  Bratton began his police career at the BPD before becoming police commissioner in New York, where his quality-of-life policy has been credited with reducing petty and violent crime.  He was recruited to lead the LAPD in 2002, following a period when the LAPD was struggling to rebuild public trust after a series of controversies in the 1990s.  Bratton presided over an era of reform and crime reduction.  In January 2014, Bratton returned to the post of police commissioner in New York, and served until September 2016.  Bratton has served as an advisor on policing in several roles, including advising the British government and is currently the chairman of the Homeland Security Advisory Council for the U.S. government