A network of more than 100 professional shoplifters toting trash bags and "customer" shopping lists is plundering Washington-area stores of thousands of dollars worth of designer clothes and elegant crystal nearly every week, department store officials say.

With the start of the new fall fashion season, security directors in some of the area's largest retail stores said the thieves, commonly referred to as "the trash bag people," are providing people with high-priced consumer goods on a steal-to-order basis.

"It's a war. We are suffering from a group of professional thieves who are making a living hitting us hard," said Lewis C. Shealy, vice president of security for Woodward and Lothrop's chain of 14 stores.

The thieves differ from randon shoplifters in that they steal only expensive, brand-name merchandise and appear to be financed by buyers who can provide them with get-away cars, false identification and money to pay bonds to stay out of jail if they are arrested, Shealy said. The thieves then forfeit the bond money and disappear.

Among the items being stolen are Calvin Klein jeans, Waterford crystal, Armani sports jackets and Lacoste sport shirts.

One Garfinckel's store detective says she arrested a shoplifter with a list for designer leather jackets in size 32 and 36 regular.

The list was so detailed it even specified the kind of key chain the buyer wanted, the store detective said.

Working in teams, the thieves can pilfer a clothes rack of a specific style, size and color and escape to a waiting get-away car in minutes. "I've never seen anything like it," said Shealy, who has been in the retail security business for a decade.

From the fall of 1978 through 1979 the thefts reached epidemic proportions for metropolitan area retailers in the District of Columbia, Northern Virginia, Montgomery and Prince George's counties, Shealy said.

A record $432 million in goods was stolen.

Stores spent $6.5 million in security and hired more than 2,000 employes to combat the thefts, according to a 1979 Greater Washington Board of Trade report.

Along with the standard security measures, some area retailers began to arm night-time security guards as the thieves became more aggressive. Newly developed chains were purchased to anchor more clothing to wall and floor racks.

Still, they said, the shoplifters have proved nearly unstoppable.

"We had the chain system [to secure clothes] but it was defeated [by the shoplifters]," said Helen Zinn, Garfinckel's security director. "It was pulled out of the hangers, in one instance, and out of the wall in another."

If possible, Zinn said Garfinckel's would secure all its goods with chains, "but we wouldn't have any customers."

At Woodies' Down Under Shop in its F street store, customers entering the shop from the Metro subway entrance are now greeted by racks of wool, leather and suede coats secured by means of metal chains. The store began chaining the clothes about two weeks ago to stop shoplifters who grabbed the coats and retreated down the subway escalator.

"I can understand why [Woodies] might need something like this," said customer Jean Moore as she waited for a sales clerk to unlock a wool coat, "but it's just terribly inconvenient. For the average person who isn't interested in taking anything, it's very inconvenient."

"It's a shame it has to be done." said another customer, Pat Guida. "But if that's what's going to deter people from stealing them, I guess it has to be done."

Despite the precautions, retailers say that the thefts are increasing. Shoplifting at Woodies is up 20 percent over the year before, Shealy said, and security costs now total $2.5 million a year.

Police and department store officials say numerous factors complicate their ability to stop the thieves. For one thing, shoplifting has a low enforcement priority for police, officers say. Moreover, highways leading from the shopping malls also provide easy escape routes for the thieves.

Because the stores keep their own arrest records, most local police don't know who the professional shoplifters are unless they arrest them, according to James Owens, chief of the misdemeanor trial section in D.C. Superior Court.

Owens said area retailers only recently have made arrangements to share their records with the police and courts.

He said the records would help them identify recidivists and convince judges to impose stiffer sentences when the thieves appear again in court.

But in some stores a fear of making false arrests also has hampered efforts to stop the thieves. At Garfinckel's, store policy prohibits detectives from searching shoplifting suspects unless the detectives actually have seen them commit a crime.

"We couldn't just stop someone who's running out with a trash bag." Zinn said. "That's how some of the stores package their bedding."

Once considered a crime primarily committed by youths, shoplifters now also include elderly and middle-aged people of various backgrounds and are harder to identify, merchants said. Thus, as part of their 1980 anticrime campaign, the merchants are launching a crime-solvers program offering reward money for information leading to the arrest and indictment of professional shoplifters.

Within the past year, Shealy said, merchants have identified more than 100 persons that have been repeatedly arrested for shoplifting.

Many of the thieves are drug addicts, out-of-towners and persons without any visible means of support. Yet they work "up and down the East Coast, hitting the (shopping) mall areas," and are apparently well financed by people purchasing the goods.

Shealy said he is convinced the thieves are part of a well-organized, highly sophisticated network of persons selling the goods to buyers running illegal as well as legitimate retail businesses.

"You can't dispose of this kind of merchandise on the street," he said. "The streets couldn't absorb all of it. It has got to be an organized effort on the part of somebody somewhere."