Behind an unmarked door, the secret surveillance bunker in the bowels of Maryland’s largest casino was humming with activity.

A manager on the gambling floor at Maryland Live had called in some suspicious behavior from one of the table-game pits, and the surveillance supervisor was blurting camera numbers like a quarterback calling an audible. Radios were crackling, and automated announcements were piped into the room every time a secured door opened on the massive Arundel Mills property.

But the focus was on the bank of 42-inch monitors at the front of the room. The surveillance team was quickly trying to determine whether a customer’s odd behavior indicated cheating or . . . something else.

“See that?” a surveillance operative asked.

“I don’t know,” another one said, staring at the screens on the wall.

The eyes in the sky never blink at Maryland Live, where officials are nearly as obsessive — and surreptitious — about spycraft as their neighbors at the National Security Agency.

And for good reason. Every month hundreds of thousands of gamblers stream into the casino, leaving behind more than $50 million in revenue. Protecting that gold mine from thieves, cheats, drunks and other threats: a security force of 200 officers and a separate state-of-the-art surveillance operation.

At Maryland Live, they’re always watching, pan-tilt-zooming, searching for wrongdoing in a place where somebody, somewhere is probably doing something they shouldn’t — usually at the expense of the casino’s bottom line.

More than 1,200 cameras in and around the casino are monitored from the dimly lit bunker, a room so secret that most of Maryland Live’s 3,150 employees don’t know its location. It’s the nerve center of the self-defense operation at the 2 million-square-foot, 24-hour casino, which is probably one of the most closely watched spaces in the capital of the modern surveillance state.

The men and women who work inside are “trained to identify things that don’t make sense,” said Rob Norton, the casino’s president and general manager, as he stood on the edge of the center one recent afternoon. “They watch for unnatural behavior and things that just look suspicious.”

Now everyone’s attention was trained on the visitor acting strangely at one of the tables. Marco Valdez, the casino’s surveillance director, squinted at the monitor, trying to decipher the customer’s body language.

Norton shifted nervously. Allowing outsiders into the surveillance center is a rare occurrence.

See previous stories in an occasional series exploring the changing casino industry and gambling culture in Maryland.

“Okay, that’s enough,” he said suddenly, before ushering a reporter into an adjacent video-review room, away from the real-time closed-circuit feeds.

Big Brother, big business

The cheaters were coming, and Maryland Live was ready for them.

For the first 10 months of the casino’s existence, it only featured slot machines. But on April 11, 2013, just past midnight, Maryland Live — already one of the country’s largest commercial casinos — added 122 live-action tables, from blackjack to baccarat. Among those in attendance for the launch: professional crooks who travel the world, looking for vulnerabilities.

“A number of known cheaters came in and tried to take advantage of us, because we were a new operation,” Norton said. To prepare for the onslaught, Maryland Live brought in specialists skilled at finding scammers who had hit other casinos. The security agents began ejecting cheats that very night.

“They really ran at us for about a month, ” Norton said, adding: “It hasn’t died down.” The casino cheats include card counters and people who try to steal chips from distracted dealers and players. They all wind up in the casino’s “black book,” which is filled with hundreds of names and faces of banned individuals.

“We’re always scanning the crowd for those people, using sophisticated systems,” said Norton, who declined to say whether Maryland Live uses facial recognition software. Norton is paranoid about divulging too many details about the casino’s surveillance operation, which might somehow give crooks and cheats an edge. In fact, he won’t even reveal how much the Arundel Mills casino has spent on surveillance, other than to say, “It’s in the millions — and growing.”

Big Brother is big business. The global market for video surveillance equipment is expected to grow to $15.9 billion in 2014, according to the analytics company IHS. Research firm Markets and Markets estimates that the $2.2 billion casino management systems market — which includes video surveillance hardware and software — is expected to double by 2018.

Beginning Monday, gambling regulators, investigators, casino officials, auditors and surveillance-system developers and manufacturers will gather in Las Vegas for the World Game Protection Conference to compare notes and war stories and learn about the latest advances in surveillance technology. Among those attending will be security experts from MGM Resorts International, which is opening a huge casino in Prince George’s County in 2016.

The stakes are astronomical. The nearly 1,000 commercial and tribal casinos in the United States generated more than $64 billion in gambling revenue in 2012, according to the most recent data from the American Gaming Association and the National Indian Gaming Commission.

Casinos are like giant banks, given how much money passes through them each day. Maryland Live officials won’t say how much cash may be in the casino at any given moment, but figures published by the state provide a hint. In 2013, Maryland Live raked in about $586 million in gross, pre-tax gambling revenue — an average of more than $1.6 million each day. And that’s just the casino’s win; it doesn’t account for the money wagered and won back by players.

“To protect all that cash in and out,” said Alan W. Zajic, a Nevada-based security consultant, “is a big challenge.”

Playing defense

Maryland Live’s surveillance center is staffed around the clock, with cameras forever watching over 330,000 square feet of restaurants, bars, cashier cages and gambling space, along with a multi-level parking garage and uncovered surface lots. They also monitor what’s going on behind the scenes, in the liquor room, the warehouse, the dice-and-card destruction room, the employee corridors and, of course, the count room, where the money is processed.

The closed-circuit system “is the latest and greatest technology,” said Valdez, the surveillance director. “We can read license plates from several hundred yards away.”

Each surveillance agent (the casino won’t say how many there are) works at a station equipped with four monitors — one with real-time video feeds; one for reviewing recorded footage; one that shows all of the property’s camera positions, which can be accessed by touch screen; and a fourth for typing reports.

Norton worries constantly about people perpetrating crimes at and against the casino. “I see 99.9 percent of the people here as genuinely good,” he said. The dishonest minority is why the casino spends so much money and bandwidth on playing defense.

There are assets to protect and a public image to maintain: Customers need to feel good about where they’re gambling, he said, which is why cashiers don’t operate behind plexiglass. Turning the property into a fortress would send the wrong message. “We want everybody who comes here to feel safe. That’s absolutely the number one thing we have to get right.”

Even as the casino has attracted hordes of people to the area — which includes a high-traffic 1.3 million-square-foot shopping mall — crime at Arundel Mills has fallen in many categories, according to Anne Arundel County police statistics.

Lt. John McAndrew, who manages police deployment at Arundel Mills, attributes the improvement to the casino’s vast surveillance and security operation. “It’s just a challenging environment to come into to engage in criminal activity,” McAndrew said.

Besides the county police presence in and around the casino, Maryland Live has a security force of about 200 officers, headed by Karen Shinham, who spent a quarter-century with the Howard County Police Department. On weekend nights, Shinham has more security officers working at the casino than are on patrol in some Maryland counties.

Still, there have been robberies in the parking lot. Cheating episodes. Counterfeit bills. Fights — including one in which a Maryland Live security officer assaulted another member of the department. A 4-year-old was locked in a car for eight hours while her mother gambled. Somebody was found carrying a gun.

According to state regulators, there were 71 thefts or robberies at Maryland Live last year. There were another 10 incidents of internal theft at the casino in 2013, including a poker dealer who was spotted putting extra casino chips into his tip box. After a surveillance review, the dealer was fired and arrested on theft and related charges.

“Our surveillance and security teams do an incredible job in keeping things from happening,” Norton said. “On those rare occasions where we do have an incident, they’re able to help bring it to a close incredibly fast.”

Last month, a 58-year-old man who’d fallen asleep in his car was robbed at knifepoint in the parking garage. The casino’s surveillance staff helped police identify a suspect vehicle in less than an hour. By the afternoon, the car’s owner had been arrested at his home and charged on seven counts, including robbery and assault. A second suspect was arrested just before midnight and charged on the same seven counts. Police officials said “the quick arrests” were due in large part to the casino’s video operation.

In a office attached to the surveillance bunker, Norton had a technician call up an archived clip.

It was July 2013. A woman was hovering at a blackjack table, observing the action. She fidgeted, looked around furtively, then grabbed four purple chips — each worth $500 — out of the dealer’s tray.

The crime was spotted instantly, Norton said, and an employee in the gaming pit triggered a panic alarm that alerted the surveillance agents. They quickly located the woman in the parking garage. She was arrested by Anne Arundel County Police before she’d left the Arundel Mills complex and is awaiting trial on a felony theft charge.

‘So easy to catch’

In the old days, surveillance operations were so primitive that they seem almost laughable now. Most casinos put catwalks or crawl spaces over the gambling floor and sent people up to monitor the action using binoculars or other “technology.”

“When I broke in in 1974, some of the places had this periscope-type thing, but instead of looking up, you were looking down,” said George Joseph, a Las Vegas security consultant. “The silly thing is that the lens was visible below the ceiling. And if you moved it, it sounded like somebody’s brakes screeching.”

In the late 1970s, Joseph put in the first 100 surveillance cameras at the Aladdin Hotel in Las Vegas. He later installed a surveillance system at the Dunes, with cameras housed “in bubbles the size of large black beach balls. They moved about two degrees a second. A little old lady with a walker could outrun the cameras.”

Reviewing footage “on those reel-to-reel monsters,” Joseph said, was a horribly inefficient process.

Fast forward to the modern systems, which often feature license plate recognition systems, tracking software to follow certain people through the casino and 360-degree, high-definition cameras that record with so much clarity that surveillance operators can zoom in after the fact — and it’s not even a fair fight for most cheaters, Joseph said. “Some of the old sleight-of-hand cheating methods — ‘capping’ or adding to a bet when you know you’ve won, ‘pinching’ or taking away from your bet once you know you’ve lost, past-posting a bet to a winning number in roulette after you know the outcome — are in the history book. They’re just so easy to catch if you follow the right procedures and are paying attention.”

Casinos use countless other protective measures and procedures, too. The red plexiglass on the blackjack tables can help employees spot marked cards. Getting to any cash box takes multiple sets of keys; no one employee can access the money alone. Garbage bags are clear, so employees can’t sneak, say, high-grade cuts of meat into the trash to retrieve later.

To Norton, it doesn’t matter if you’re trying to cheat the casino out of a few $25 chips or if you’re stealing food. It’s all coming out of the bottom line. “I have zero tolerance for any sort of theft,” he said.

“Ever see that movie ‘Casino’?” he asked, standing on the gambling floor.

There’s a scene in the film where the fictional casino’s boss — played by Robert De Niro — explains the way things work in the gambling world: In Vegas, everybody’s gotta watch everybody else. Since the players are looking to beat the casino, the dealers are watching the players. The box men are watching the dealers.

On down the line he goes, until he says: I’m watching the casino manager. And the eye in the sky is watching us all.

The movie came out nearly 20 years ago. The riff still stands, Norton said.

Nearby, several jumpsuit-clad employees were extracting locked and loaded money boxes from some of the casino’s roughly 4,300 slot machines. They were placing them in a rolling metal cage, which was guarded by uniformed security officers.

“Surveillance is watching this right now,” Norton said. He smirked, then added: “They’re always watching.”