Acting Chief Peter Newsham joined the MPD in 1989 and rose quickly through the ranks, serving in a number of district operational assignments. Chief Charles H. Ramsey promoted him to Commander of the Second District in January 2000.
In June 2002, Newsham was promoted to Assistant Chief in charge of the Office of Professional Responsibility (OPR), which included the Internal Affairs Division, Civil Rights and Force Investigation Division and Compliance Monitoring Team, responsible for overseeing the MPD's Memorandum of Agreement with the US Department of Justice. Newsham took the position of Assistant Chief in Charge of ROC-North in July 2004.
On September 23, 2007, Chief Lanier announced a reorganization to the Metropolitan Police Department and put Assistant Chief Newsham in charge of the Internal Affairs Bureau. In 2009, Assistant Chief Newsham was named the Assistant Chief of the Investigative Services Bureau. Mayor Muriel Bowser appointed Newsham Interim Chief of Police on September 15, 2016; he was named Chief of the Metropolitan Police Department on February 23, 2017.
Newsham holds a bachelor's degree from the College of the Holy Cross and a law degree at the University of Maryland School of Law. He is a member of the Maryland Bar.