A cadre of detectives, many of them former agents from the Secret Service, FBI, Customs Service and military, toil on the second floor of an office park that from the outside looks like any other in the Tysons Corner area.

Their windows look out onto gas stations, shopping malls, concrete buildings and a steady stream of traffic. But what grabs their attention in all the economic hustle and bustle in America today is money laundering, a crime so pervasive that President Clinton has declared it a national security threat.

This relatively secretive shop in Vienna, a few miles down the road from the CIA, is the headquarters of the Financial Crimes Enforcement Network, or FinCen, a unit of the U.S. Treasury Department that acts as a library of suspicious activity information gathered from banks, credit unions, brokers, casinos and other financial institutions.

Visitors who step off the elevator are greeted by armed guards and a policy that no photographs be taken.

FinCen is part regulator, making sure that banks, brokers and others have systems to detect suspicious activity and that they formally report these episodes as required. But after gathering that information, the agency's 170 employees spend most of their time analyzing it with high-speed computers to link suspected individuals to bank accounts, businesses, real estate and other assets.

The agency, which does not itself investigate crimes, then provides that information to federal and state law enforcement officials across the country to help them see patterns of behavior that in turn will help them ferret out crime.

Publicity surrounding a federal probe into whether some of the $7.5 billion that traveled from Russia through the Bank of New York was laundered funds has put financial crime in the spotlight. To combat the public perception that the government has been too lax on money laundering, which is estimated to entail more than $300 billion a year in the United States, lawmakers in the House and Senate in the past two weeks have proposed tough new laws. Attorney General Janet Reno and Treasury Secretary Lawrence H. Summers joined the bandwagon, announcing they too will propose new get-tough regulations and law.

The proposals all call for expanding the information collected by FinCen.

But FinCen has been criticized by industry and government officials for not doing enough with the information it already gathers.

Among the key complaints: FinCen lacks a computer system to analyze in depth many suspicious activities, it hasn't sufficiently educated law enforcement about its resources, and the agency hasn't kept bankers and other executives informed about how the information they are required to file, often at great cost, is used.

Officials at the FinCen, which is only 10 years old, are the first to agree they need to do a better job.

"We've begun aggressive programs to address the concerns that have been expressed to us both by law enforcement and the regulated industries," said James F. Sloan, who became FinCen's director in April after a 21-year career in the Secret Service and eight years in local law enforcement as a police officer and detective in New Jersey.

The report card hasn't been all bad. Industry and government experts say that FinCen does a first-rate job analyzing the information it collects on large cash transactions. Banks, casinos, brokerage firms, and non-bank check cashiers and wire transfer firms all must file with FinCen a report on any cash transaction over $10,000.

Using artificial-intelligence software, FinCen computers can sift through trillions of bits of information from the 12 million of these reports it receives each year. Then the computers spit out beautiful charts diagraming relationships between dozens, sometimes hundreds, of individuals, bank accounts and businesses. Law enforcement agents can use these charts, for example, to demonstrate to a judge why they need a search warrant for a particular company.

John Byrne, senior counsel for the American Bankers Association, says the industry likes filing reports with FinCen rather than having to file with many federal agencies, as bankers and others used to have to do.

But the agency has not yet developed a similarly sophisticated computer analysis for questionable non-cash transactions that banks must formally report in what are called "suspicious activity reports," or SARs. And neither FinCen nor the FBI or other agencies that rely on FinCen data have done a good job telling banks what's done with the information in the SARs.

That irks banks, which have filed 325,000 SARs since April 1, 1996. And now the Clinton administration and Congress is proposing expanding the list of who must file SARs to include brokerages, casinos and all the other companies that already must file reports on cash transactions above $10,000.

"What we want to know is whether the information has been used to start an investigation, if it's been useful in a prosecution, what agency is looking at it," said Bryne, who now co-chairs, with FinCen Assistant Director David Vogt, a Treasury task force looking into how to improve communication with industry. "We used to send the SARs in and they would sit there."

Industry executives say they understand that federal law enforcement agencies don't have the resources to investigate every suspected crime but say having more information would still be helpful.

For example, Bryne said, in major U.S. cities such as New York, Boston and Miami banks know that a potential crime involving less than $100,000 is unlikely to be investigated by a federal prosecutor, even though by law the bank must report it. If a bank were to be told that formally, then it could more easily approach local police about a possible investigation, he said.