The first JTTF was established in 1980 in New York City, with ten FBI special agents and ten New York City Police Department (NYPD) detectives. In 1999, prior to the attacks of September 11, 2001, the United States had 26 JTTFs; shortly after the attacks, FBI Director Robert Mueller instructed all FBI field offices to establish formal terrorism task forces. As of the end of December 2011, there were more than 100 Joint Terrorism Task Forces nationwide, the vast majority established after the 9/11 attack. There were 113 JTTFs as of 2013.