NEW YORK (CBSNewYork) — More than 5 million people ride the New York City subway every day, and mixed in with all the subway riders are a special team of NYPD officers.

CBS2’s Andrea Grymes got an exclusive behind-the-scenes report.

In a crowded subway car, plainclothes police officers are not usually to spot. One subway rider told Grymes she had not seen any police on the subway that day – but it just so happened that the woman sitting next to her was a plainclothes officer.

Officer Lauren Garcia of NYPD Transit District 30 blended into the crowd with jeans, sneakers and a shopping bag.

“Especially like when I walk up to people, they’re like taken aback: ‘Oh my gosh, you’re a cop?’” Garcia said.

Garcia was actually one of six plainclothes officers on the subway car, which was headed from Brooklyn to Canal Street in Manhattan at the time. They are all members of the NYPD Anti-Crime Team in Transit District 30 in Downtown Brooklyn.

“We’re going to be looking in particular for what you have in your hands,” said NYPD Transit District 30 Commanding Officer Capt. Zahid Williams.

The team is one of the NYPD special units that targets specific suspects and specific problem spots in the subways – working to prevent and fight crime.

“We have our recidivists for our robberies, four our grand larcenies, for our swipers – our swipers are people that are offering swipes for sale,” Capt. Williams said.

Across the city, transit crime is down – about 3 percent.

But sex crimes such as groping or public lewdness, however, are up by 29 percent. Police attribute that increase to more victims now choosing to come forward.

Robberies across the board have plunged about 9 percent – in a trend police attribute in large part to undercover work.

“I have the vest on, have the gun, handcuffs,” said NYPD Transit District 30 Lt. Michael Catusco, who was dressed as a construction worker.

The undercover officers also disguise themselves at Metropolitan Transportation Authority workers, or headphone-wearing riders – looking distracted, but secretly watching everything.

Even behind station doors, the officers keep an eye on the turnstiles.

“Someone may be here trying to rob someone and so forth, so there’s a lot of things you can actually see,” an undercover officer said.

For the anti-crime team, the busiest time of day is actually during business hours. For NYPD Transit as a whole, the busiest time of year is actually coming up – the holiday season.

“Someone who last month was reading a book on the train is now going to have an expensive item next to them,” said NYPD Transit Chief Joseph Fox.

Police reminded riders – especially shoppers –- to be alert and pay attention. Chances are plainclothes officers on your car or platform will do the same.

Fox told CBS2 many people do not even know they are victims of crime until sometimes hours later, when they realize something was stolen.

The officers in Grymes’ report were plainclothes and not undercover, and the NYPD allowed their faces to be shown on television.