Who is Chief James O'Neill?

New York City Mayor Bill de Blasio said Chief of Department James O'Neill will replace Commissioner Bill Bratton in September.

An Irish-American raised in the Flatbush section of Brooklyn, Chief O'Neill started as a transit cop patrolling the city subways.

The mayor credits Chief O'Neill with being the architect of the department's community policing program. Neighborhood policing will continue and expand under his new leadership.

Chief O'Neill said he knows the department still needs work to improve relations especially in the city's most crime-ridden neighborhoods. He takes over for a commissioner who has a long history in law enforcement.

O'Neill's mother Helen and sister Sheila were with him at Tuesday's surprise announcement.

O'Neill's official bio from the NYPD's website:

Chief of Department James P. O'Neill was appointed to the New York City Transit Police Department in January 1983, and began his career on patrol in Transit District 1. He was promoted to Sergeant in September 1987; Sergeant Special Assignment in April 1991; Lieutenant in August 1992; Lieutenant Special Assignment in August 1995; Captain in November 1997; Deputy Inspector in December 2001; Inspector in August 2003; Deputy Chief in October 2005 and to Chief of Patrol on June 2, 2014. He has served in Transit Districts 1, 3 and 11; the 25, 44, 52 and Central Park Precincts, the Firearms Training Section, the Police Academy, Warrant Section, SATCOM Detective-Narcotics Operations, the Vice Enforcement Division, the Narcotics Division, the Fugitive Enforcement Division, and the Office of the Police Commissioner.

Chief of Department O’Neill most recently served as Chief of Patrol. He also served as Commanding Officer of the Office of the Police Commissioner, the 25, 44 and Central Park Precincts, the Vice Enforcement Division, the Narcotics Division, as well as the Fugitive Enforcement Division. He has also served as Executive Officer of the 52 Precinct and SATCOM Detective Narcotic Operations.

Chief O'Neill holds a Bachelor of Arts degree in Government and a Master of Public Administration degree from John Jay College.

Chief O’Neill becomes the 38th individual to hold the post, which prior to 1973 was known as Chief Inspector and from 1973-1985 as Chief of Operations.