In New Brunswick, N.J., a building superintendent opened the door to apartment No. 1076 one balmy Tuesday and discovered an alarming scene: terrorist literature strewn about the table and computer and surveillance equipment set up in the next room.

The panicked superintendent dialed 911, sending police and the FBI rushing to the building near Rutgers University on the afternoon of June 2, 2009. What they found in that first-floor apartment, however, was not a terrorist hideout but a command center set up by a Secret Team of New York Police Department.

From that apartment, about an hour outside the department's jurisdiction, the NYPD had been staging undercover operations and conducting surveillance throughout New Jersey. Neither the FBI nor the local police had any idea.

Since the terrorist attacks of Sept. 11, 2001, the NYPD has become one of the country's most aggressive domestic intelligence agencies. A months-long investigation by The Associated Press has revealed that the NYPD operates far outside its borders and targets ethnic communities in ways that would run afoul of civil liberties rules if practiced by the federal government. And it does so with unprecedented help from the CIA in a partnership that has blurred the bright line between foreign and domestic spying.

The department has dispatched teams of undercover officers, known as "rakers," into minority neighborhoods as part of a human mapping program, according to officials directly involved in the program. They've monitored daily life in bookstores, bars, cafes and nightclubs. Police have also used informants, known as "mosque crawlers," to monitor sermons, even when there's no evidence of wrongdoing. NYPD officials have scrutinized imams and gathered intelligence on cab drivers and food cart vendors, jobs often done by Muslims. Many of these operations were built with help from the CIA, which is prohibited from spying on Americans but was instrumental in transforming the NYPD's intelligence unit.