In September of 1980, Sgt Matthew Stannish & "The Dirty Dozen" of the Transit Police were sent to Philadelphia to train with the Philadelphia K-9 unit. Their first day of patrol was on December 15th, 1980.  Once on patrol, the unit proved time and time again to be an effective tool in the prevention of crime and the apprehension of criminals in the transit system.

As part of his mayoral campaign, candidate Rudolph Guiliani pledged to end the long unresolved discussion and merge all three of New York City's police departments (the NYPD, the Transit Police, and the NYC Housing Authority Police Department) into a single coordinated force.  Mayor Guiliani took office on January 1, 1994, and immediately undertook to fulfill his promise and end a problem that had defied final solution for almost half a century.  Discussions between the city and the NYC Transit Authority produced a memorandum of understanding, and on April 2, 1995, the NYC Transit Police was consolidated with the NYPD to become a new Bureau within the NYPD.  Upon merging with the NYPD (in what was coined "The Hostile Takeover"), the NYC Transit Police K-9 Unit and the NYPD Precinct based K9s were absorbed into a new, centralized sub-unit of the NYPD Emergency Service Unit, becoming ESU K-9. In June 2006, the NYPD Transit Bureau re-deployed it's own K-9 Unit devoted exclusively to patrolling the most extensive  public transportation system in the country. Their overall mission is securing New York City's mass transit system against a terrorist attack with the added benefit of preventing crime in the NYC Subway.