They looked like any other shoppers browsing iPads and Apple Watches at the Apple Store in Towson, Md.

But a security guard saw something amiss in the behavior of the four men in the store at Towson Town Center. Two of them — one wearing a blue jogging outfit, the other dressed in black pants and shirt — were acting as lookouts, blocking the views of sales associates. The other two were scooping up display items and slipping them into their vests. Then they all headed for the exit.

They didn’t get far. They were stopped by security guards, and police arrested three. The men, all from the Eastern European nation of Georgia, had driven down from New York in a minivan, police and prosecutors say. Inside, they say, officers found dozens of Apple devices.

The men were accused of stealing more than $1,500 worth of iPods and software. They were convicted last year of theft.

For retailers, simple shoplifting is an unavoidable cost of doing business. But now, industry analysts and law enforcement officials say, a greater threat is emerging: theft and fraud by highly organized criminal rings.

The high-stakes enterprises often operate across state lines. They might employ teams of “boosters” — often the homeless or the drug addicted — who go into stores to steal everything from laundry detergent and baby formula to designer clothes and diamonds. They fence stolen goods at pawn shops, kiosks, vans on the street and, increasingly, online auction sites.

And they’re becoming more brazen and more dangerous, analysts say, in some cases attacking store employees and even shoppers.

“We probably see organized retail crime incidents across our stores every day,” said Jim Cosseboom, manager of investigations and corporate asset protection for the supermarket operator Ahold USA, parent company of Giant, Food Lion and other chains.

“What they’re targeting is always shifting,” he says, from detergent to razor blades to seafood. But it’s anything “that can easily be sold for quick cash. …

“It’s a significant concern.”

Organized theft has surpassed internal theft to become the leading cause of retail loss, said Robert Moraca, vice president of loss prevention for the National Retail Federation. Analysts say the increase has been fueled by the opioid epidemic and by the growing understanding among criminals that theft can be quick, easy and profitable.

In a well choreographed assault, Moraca says, thieves can clear shelves of thousands of dollars’ worth of goods in minutes.

“And that’s happening in multiples,” he says. “It’s not just a group that gets together and wants to steal. These are groups that already exist for criminal purposes,” such as drug trafficking and human trafficking.

“These are hardened criminals, and they get into organized retail crime because it’s extremely profitable.”

Individual retailers contacted by The Sun were reluctant to discuss details. But the National Retail Federation reported that organized crime cost retailers $30 billion last year. The group recently surveyed retailers on organized crime; all of the respondents said they had been victimized in the previous year. They said they were spending an average of $545,000 on employees dedicated to fighting organized crime, an all-time high.

Coordinated efforts between retailers, store security, law enforcement and prosecutors have helped, analysts say, as has the emergence of associations focused on fighting organized retail crime. The Mid-Atlantic Organized Retail Crime Alliance, which includes Maryland, brings together retailers, law enforcement, security and loss prevention officials to share data and intelligence on organized theft, robberies, counterfeiting, check and credit card fraud and other scams.

Thirty-four states have enacted laws against organized retail crime. Maryland has not. The Maryland Retailers Association wants legislation that would distinguish between organized retail theft and other types of theft.

“Being on the I-95 corridor, we are particularly susceptible to organized retail crime,” association President Cailey Locklair Tolle says. “Shoplifting in Maryland, both the instances of theft and the dollar amount that’s stolen every year, has steadily been on the rise, and part of it does have to do with organized retail crime.”

The group is concerned that the increase in the state threshold for felony theft from $1,000 to $1,500 last year will encourage more organized rings to operate in Maryland. The Governor’s Office of Crime Control and Prevention looked at theft classifications last year and recommended that lawmakers begin to assess the impact of organized retail crime by developing a definition of the activity to include in Maryland Uniform Crime Reports.

The retailers group plans an informal meeting Monday in Annapolis with members of the Maryland State’s Attorney’s Association, law enforcement, loss prevention officials and lawmakers to start hashing out solutions. Current theft laws, Tolle argues, fail to address the unique nature of organized crime, with high-level criminals directing lower-level offenders to steal, stealing hundreds of thousands of dollars worth of goods and often operating across county lines.

“We need to think about capturing these guys at the lower level to stop these cycles,” Tolle said. “People will say, ‘People are stealing because they are hungry. “That does happen. But we’d like to draw a line between non professional theft and (individual) theft.”

At Home Depot, employees are told to leave suspected shoplifters to trained security workers. A spokesman for the home improvement retailer says shoppers never should try to chase or stop a suspected thief.

“The individuals who are doing the shoplifting have become extremely dangerous, much more than anyone would think of a petty shoplifter doing,” spokesman Stephen Holmes says. He says assaults on security guards and asset protection personnel have become common.

“It can be the slightest thing that triggers that act of violence,” he says. “I just don’t think the average person realizes what’s going on.”

Twenty-two people were charged last month an alleged national ring accused of stealing $20 million worth of goods from malls across the country over a decade, including at least one store in Maryland.

Brandon Ramirez Salas, a 22-year-old from Mexico, and others are accused of trying to steal merchandise from the Hollister Co. store in Frederick’s Francis Scott Key Mall in October 2015. They planned to deliver the merchandise to another defendant in San Diego, prosecutors said in an indictment.

Prosecutors say the defendants, all from the San Diego area, formed crews of thieves who stole from stores throughout the United States and transported the goods for sale in Mexico.

Team leaders would scout stores and use cell phones and hand signals to direct other team members, prosecutors say. “Mules” would take merchandise from stores in “booster bags” — shopping bags with metallic linings designed to deflect sensors, prosecutors say. “Blockers” would prevent employees from seeing the theft by distracting them, using clothing to obstruct their view or physically restraining them, prosecutors say.

Prosecutors say one defendant knocked over an infant in its stroller and injured the father to avoid being arrested for a theft at a Hollister store in Schaumburg, Ill.. Another defendant drove a vehicle through a crowd while fleeing from a theft at a Hollister store in San Diego, they say.

At one suspect’s San Diego area home, prosecutors say, investigators found trash bags of new clothing, with merchandise tags and security devices still attached, from Victoria’s Secret, Hollister, Guess, Express, Abercrombie and Fitch and other stores, and brands such as Calvin Klein, Hurley, Armani, Adidas, Kenneth Cole and Puma.

Near the clothing, prosecutors say, investigators found piles of new Louis Vuitton shoes.