Every so often the frustration at J.W. Ayers Variety & Hardware rises so high that management puts a pegboard in the front window displaying samples of goods that have been stolen from the store recently. Sometimes there are 50 items or more hanging from the board.

"It lets the honest people know what's going on," says Ronald Kaplan, whose family owns and operates the popular North Arlington store, "but I'm not sure what good it does, because the dishonest people already know what's going on."

What's going on at Ayers -- and at stores across the country, at an estimated cost to retailers of $10 billion a year -- is rampant shoplifting.

The perpetrators are not just teenagers, although youths are disproportionately accountable, especially in music, book and toy stores. They're not just poor people, either. The profile of a typical shoplifter in a given store generally mirrors the demographics of the store's clientele. And overall, across all retail segments, shoplifters run the gamut of age, sex, race, education level and socioeconomic class. "It's known as the second-oldest profession," says Lee Pernice, a spokeswoman for Sensormatic Electronics Corp., which specializes in anti-theft systems.

While there are professional shoplifters out there, most are amateurs. "The typical shoplifter doesn't do it for the money," says Bill Zalud, the editorial director at Security magazine, a trade journal specializing in the subject, "they do it for the rush." At Ayers, for instance, a kid in a Boy Scout uniform, a man with a PhD, a June Cleaver-looking woman, even a judge are among those who have been caught in the act. ("The bad guys look just like the good guys," says Kaplan, and experts agree with him.)

What do these thieves pilfer? Anything -- usually the smaller the better. Compact discs, tobacco products, health and beauty aids and clothes are favorite targets nationally. At Ayers, they take pens, drill bits, toys and, of course, candy. But also thread, knitting needles, packaged underwear and denture cream.

So what's a store owner to do?

One option is electronic monitoring. Such systems can be expensive. Potomac Mills Mall, which prides itself on 24-hour-a-day security and has a Prince William County police substation on the premises, spent $400,000 in electronic security upgrades alone in 1997, according to the mall's general manager, Jim Ralston. Such systems are Big Brother-ish, and they're becoming increasingly sophisticated.

They can watch not only customers but employees, too, which is important because employee theft is a more costly problem than shoplifting in the United States. (It accounts for an estimated $16 billion annually in retail losses.)

These systems -- which can include closed-circuit TV cameras, electronic article surveillance (tags, attached by retailers, that set off alarms if items are stolen), source tagging (tags attached to items in the manufacturing stage), mallwide paging systems and even remote video and audio monitoring by a centralized agency far offsite -- have at least three advantages, according to Zalud: They are a visible deterrent; they alert trained security personnel to a shoplifter in real time; and they provide identification of the thief in court.

For all merchants, especially those not inclined to use electronic security, Zalud, Pernice, Ralston and other experts say, the keys to deterrence are the store's layout and its sales staff:

* The layout should be as open and well lit as possible, to allow employees to see all parts of the store. "One critical element for most shoplifters is privacy," says Zalud. "They want to make sure they're not being watched. You need to make sure they have no place to hide in the store."

* The staff should be trained to greet customers because, among other things, doing so lets them know somebody knows they're there.

* The staff should be trained to watch unobtrusively for telltale shoplifter behavior -- furtive glances, sudden hand movements, general nervousness, stretching, yawning, loitering.

* The staff should be trained to be circumspect if a theft is witnessed. For reasons of safety and liability, and to avoid potential charges of false imprisonment, civil rights violations, malicious prosecution or even slander, "no employee, including the store manager, should take it upon himself to make an arrest," Zalud says. "Let sworn officers of the law handle that."

Back at Ayers, Ronald Kaplan, who has heard most of this before and whose store often prosecutes offenders, laments that -- ironically -- upstanding patrons contribute to the problem. "It bothers them to be watched, so we can't keep watching people without alienating our honest customers . . .

"I've been in the retail business since 1971, and not once has an honest person come up to me to say they've seen someone stealing something. They just don't want to get involved."

Instead, everyone everywhere is being watched, and at Ayers these days the underwear display is under lock and key.

Bill O'Brian is a Magazine copy editor.