A team of 104 NYPD officers is the city's first line of defense when it comes to terror threats on the subway.
The NYPD transit bureau's anti-terrorism unit is focused on uncovering threats and thwarting attacks on the subway, which has been under tighter security in the 11 years since the Sept. 11, 2001, attacks.
Whether on foot or scooters, officers in the unit search the MTA's busiest stations daily, largely during the morning and evening rush hours, for suspicious people and packages.
"Our main focus is the prevention of terrorism within the transit system," said Lt. Jose Medina, a 16-year police veteran who has been with the unit for more than two years. "It's an enormous responsibility, obviously, because we have millions of people who travel through the subway system."
The unit, which was created in 2010 and funded with federal stimulus money, also pitches in on Metro-North.
Though police officials wouldn't say exactly how many terror-related cases the unit has been involved with, Commissioner Ray Kelly has said there have been at least 14 terrorist plots thwarted citywide since 9/11, including some targeting the subways.
"Thank God -- knock on wood -- we haven't had any major happenings within the subway system," said Medina, 44. "We've been blessed so far."
Riders are accustomed to seeing teams of officers at busy station entrances, randomly selecting people with bags to see whether they're carrying anything that's illegal to bring into the subway system.
Don't try to slip away if you've got a bag, said Capt. Roberto Cruz. There are always at least two undercover officers watching for anyone trying to avoid police.
Cruz said the team tries to vary when and where it does bag checks, or "surges" of officers at stations, though his unit mostly focuses on the MTA's busiest and most iconic stops, including Herald Square, Penn Station, Times Square, Union Square and Grand Central Terminal.
"We try to be unpredictable," said Cruz, 36, a former Marine who has been an Air Force reservist since 2009. "It's mostly a show of force to reassure the public that we're out here doing something."
Inside the turnstiles, some officers drive around on electrically charged T-3 scooters that elevate them a few feet above most riders' heads.
"People can see you from far," said Officer Marlon Minaya, adding that being able to move at up to 12 mph helps him reach incidents more quickly.
All officers in the anti-terror unit carry radiation detectors on their belts. While the cops said it was uncommon for the detectors to go off, they might if a passing rider has recently had a stress test or undergone chemotherapy.
On a recent Tuesday morning, a sergeant and eight officers lined up outside the doors of each No. 2/3 subway car entering the 42nd Street-Times Square station, and quickly inspected the cars before giving the train's conductor an "all clear." The drill, called Train Order Maintenance Sweeps -- or "TOMS" -- would be repeated dozens of times over the 81/2-hour shift. A similar operation, Mobile Order Maintenance Sweeps -- or "MOMS" -- is done when officers ride a train and step out at each station.
Sgt. Marc Richardson, who joined the unit at its inception in 2009 after five years as a cop in Jamaica, said the different environment brought several challenges.
"You could have a subway slashing in a closed subway full of people. That's very difficult to handle," said Richardson, adding that at times he does patrols on his own, unlike some officers above ground, who drive around with a partner. "Our backup may be two, three, four stations away."