A story recently published by the online news site Gothamist about an undercover police officer who allegedly infiltrated a group of law-abiding Muslim students at Brooklyn College is raising questions about the NYPD's intelligence unit.

The students, unnamed in the article, told Gothamist that a woman who called herself "Mel" attended weddings and other events with the students, even going through the motions of converting to Islam. The students believe she is the same NYPD officer who, several years later, helped federal investigators put together a case against two Queens women accused of planning to build a bomb.

Deputy Commissioner of Intelligence and Counter-Terrorism John Miller says the police are only able to conduct this type of surveillance if there is a named target and probable cause to believe there was a possibility of some sort of crime or terrorist plot. 

Speaking with WNYC, Miller said "There's truth in the Gothamist story, if you pick out certain facts you can say, 'Well, this is true,' or 'That's true', but it's wrapped around this narrative that there was this over-arching blanket surveillance, which is not the case."

Miller described his field as a difficult one, requiring a balance between protecting the public from attacks and not invading people's privacy or infringing on their rights.

"We have two sets of tensions that pull against each other every day," he said. "The hardest thing we have to do is find a balance. Because neither one is more important than the other."