Commander McMahon graduated from the police academy and later from the University of LaVerne with a BA in Business Administration. Commander McMahon is also a graduate of the West Point Leadership Academy.

As a police officer, Commander McMahon worked a variety of patrol
assignments, which included assignments as an undercover narcotics
officer, gang investigator, staff writer and a Senior Lead
Officer.

He was promoted to sergeant in 1996. In addition to being a field
supervisor, he served as an Assistant Watch Commander to patrol
operations at Wilshire Area, supervised a staff responsible for
preparing directives regarding Department policy and procedures for
the Chief of Police and was also assigned to Internal Affairs as a
member of the Rampart Corruption Task Force.

He was promoted to lieutenant in 2001. In his twelve years as a
lieutenant, he has worked as a watch commander, administrative
lieutenant, detective commanding officer, and as the Officer in
Charge when Operations-Valley Bureau first implemented it’s Violent
Crime Task Force. It was this task force that, under his
leadership, received great accolades and positive publicity for
exceptional productivity and the noteworthy number of high-profile
arrests along with a significant amount of gun and narcotics
seizures. He went on to Central Area and became the Gang Impact
Team Officer in Charge. In his four years, this group consistently
led the City in narcotics arrests.

Prior to his promotion to captain, McMahon was the adjutant to the
Commanding Officer, Counter-Terrorism and Special Operations Bureau
(CTSOB). In this assignment, he provided support to the commanding
officer’s oversight to the bureau’s five divisions: Metropolitan,
Major Crimes, Air Support, Emergency Operations and Emergency
Services. This assignment has given him the opportunity to travel
to Abu Dhabi and Dubai to showcase to this region of the Middle
East, the Department’s counter-terrorism capacities and
capabilities.