"Opportunity" thefts in Alexandria office buildings have been on the upswing over the past 10 weeks, according to Alexandria police.

Since June 1, Alexandria's Department of Public Safety has counted over 44 thefts of purses and wallets from offices where an employe temporarily leaves to go to the washroom, run an errand or grab a bite to eat.

About 22 of the crimes occurred in office buildings in the downtown area bounded by the George Washington Masonic Memorial, Powhatan Street, the Potomac waterfront and Duke Street. Another 22 thefts occurred in offices in the West End, including those in the 5100 through 5900 block of Duke Street and in the Alexandria Hospital, Southern Towers and The Hamlets on or near Seminary Road.

"We have some going on all the time. But periodically we have upswings where someone is looking for the opportunities. We're coming off one of those right now," said Officer John D. Kochensparger of the police department's crime analysis unit.

The office thief's method is fairly predictable, police said, and is not intended to arouse suspicion. "They say they're looking for a job or a fictitious person. Or they pretend they're in the wrong building at the wrong address," Kochensparger said.

High-rise office complexes are often picked because a number of offices can be hit in one trip, Kochensparger said.

"Sometimes we'll find purses and wallets in the stairwell of buildings or in the men's room. Frequently what they'll do is steal a purse, take the money and credit cards -- you may find the purse in a toilet tank or in the trash," the officer said.

"By the time they get down to the lobby, they won't have a purse or a pocket bulging with wallets," he added.

In one incident, a man dressed in the blue uniform of a maintenance worker stole money from offices in the Courthouse Square building in the 500 block of King Street. Because of the uniform nobody questioned him, but police said office workers should have. Maintenance men in that building wear only brown uniforms.

Although the property of female employes (a purse typically kept beneath the desk) is frequently taken, the opportunity thief also looks for wallets in male workers' jackets left hanging on a chair or coat rack.

Alexandria police have recently alerted a number of office building property managers about the increase in thefts, asking them to warn workers in their buildings to place purses and wallets in a locked file cabinet or desk drawer.

Kochensparger suggested that if visitors look suspicious or out of place, workers should challenge them by asking if they need help. "That could scare them away," he said.

Because of this summer's surge in these types of crime, Alexandria police became suspicious of a man who had previous arrests for office thefts. Police recently arrested and charged a 21-year-old Arlington man with several thefts in Old Town and West End offices.

The man also confessed to committing 60 other office thefts that occurred between February 1984 and May of this year in exchange for immunity from prosecution in those cases.

The man, impeccably dressed as he made his office rounds in a make-believe search for the maintenance office, told police that stealing from unguarded offices was "easy money."

Many such thefts could be prevented if people would be more wary in the work place, said Sgt. Ronald E. Uhrig, head of the patrol coordination unit.

"There's a feeling of security like you would have in your home. You work in a familiar environment with the same people and you don't read from that the potential for things to be stolen," Uhrig said.