When the national headquarters of the U.S. Marshals Service moved from Washington to Tysons Corner Center in 1979, many employes breathed a sigh of relief: a lot less traffic, a lot more space.

Next year, the country's oldest law enforcement agency will move back inside the Capital Beltway, and employes are delighted for the same reasons as before.

"What was really good 10 years ago has really become an untenable situation," said Gary Mead, associate director for administration of the Marshals Service, which tracks down fugitives, guards federal prisoners, protects government witnesses and investigates threats on public officials.

Fairfax County has seen extraordinary development in recent years, and the U.S. marshals' headquarters is no longer a welcome tenant in the regional shopping center, which is undergoing an expensive renovation.

Developers are spending $150 million to spruce up the mall at routes 7 and 123 to keep up with competition. There will be room for as many as 100 new specialty shops and more department stores that will join big-league retailers such as Bloomingdale's.

There won't be room for bureaucracy.

"We wanted them to leave because we don't need that kind of operation in the center. We wanted to convert it to retail space," said Geoffrey Donoghue, a vice president for the Lehndorff Group, the Dallas-based firm that is developing the mall.

For eight years, the 325 staff members in the Marshals Service headquarters have quietly occupied three floors in the mall, tucked away from the hustle and bustle down a corridor on the mall's east side.

When errant shoppers stroll up to the guarded double doors of the headquarters -- which is equipped with television monitors, light sensors and electronic access codes -- they are quickly shooed away by security.

The low-profile location has had its drawbacks.

Said Stanley Morris, director of the agency: "Can you imagine what it's like telling people to go beyond Bloomingdale's and past the pet shop and you'll find the world's oldest law enforcement agency? But we've survived."

It has been difficult at times. In an agency with about 3,000 people in 300 offices from Guam and Alaska to Puerto Rico, marshals are still trying to get people to spell their title with one "l," and even to convince them that the agency exists -- now that "Gunsmoke" is off the air, the director said.

The headquarters in the mall handles administrative work and much of the coordination of investigations. The government offices are next to where Nordstrom, the successful West Coast department store, will be next year.

With mall renovation at the midway point, marshals service officials said the timing could not be better. Their lease is up next July.

"Needless to say, we're not happy being here any longer," said Morris. "Needless to say . . . we're not viewed as the kind of tenant they need. This is a source of the most valuable retail property. And they've got a bunch of bureaucrats here."

In any case, the director added jokingly, the mall landlords "better not {bother} us. We've got the guns and handcuffs."

Three government agencies, including the Marshals Service, a classified map publications annex and a defense management agency, were told in the past two years that their leases would not be renewed, according to Donoghue.

In one of the Washington area's hottest commercial markets, the space in Tysons Corner Center will rent from $30 to $125 per square foot per year, Donoghue said.

The Marshals Service headquarters will move to a site inside the Beltway in Northern Virginia, which will be announced in the next few months, said a spokesman for the General Services Administration.

The plans are to consolidate the headquarters with the Drug Enforcement Administration as part of a recent effort to create better efficiency by teaming up major federal agencies, the spokesman said.

The impact of renovation already has been felt.

For the past 18 months, Mead has kept his office curtains drawn to shut out the sound of the drills.

With the area's increased traffic, the mall construction and their own cramped quarters, Mead said many at the Marshals Service will not miss Tysons Corner Center. "Over the last four years, the enthusiasm among employes has waned," he said.

The agency's director said he does not have the time to shop anyway. After an interview Friday, Morris flew to France, where he will attend a conference of Interpol, the international police organization.

Morris said he had hoped that his headquarters would have pulled out of the shopping mall before the holidays.

"This is not the place to be the day after Thanksgiving through til Christmas," he said.