When the American Federation of Teachers suspected one of its locals, the Washington Teachers Union (search), of some bookkeeping hanky-panky, it called on a professional to unravel the case.

Police detective? Private eye? No. The national union called on Bruce Dubinsky, forensic accountant.

Forensic accounting is "very different from regular accounting," said Dubinsky, noting his "professional skepticism" and investigative approach. "It's not finding what you can see, but seeing what you can find."

Dubinsky tracks corporate fraud, peeling away layers of fake numbers, phony names and false records to dig up the white-collar dirt.

It's different from crime-scene forensic work. Instead of a lab, Dubinsky works out of an airy Bethesda office. Instead of a white lab coat, he wears a business suit. Rather than combing torn clothing, Dubinsky and his colleagues at Klausner, Dubinsky and Associates comb through corporate books, looking for oddities that could signal swindles.

The cases they investigate can be extremely complex, involving thousands of pieces of evidence. Dubinsky said a typical case involves crates and crates of documents and thousands of computer files.

"By the time I get in, it's tens of thousands of dollars" of possible fraud, he said.

Sifting through those files, investigators flag relationships or patterns that would not normally occur. Sophisticated software helps in this phase.

"Fraudsters often use the same pattern most of the time," such as always making up company names with three letters, Dubinsky said.

With documentation in hand, the investigation moves into personal interviews.

"You'd be amazed what people will tell you when you sit to talk to them," everything from implicating co-conspirators to blanket denials, Dubinsky said.

Convincing people to talk is important for forensic accountants, who do not have access to the police tools, such as subpoenas, that can compel people to talk.

"We have to be more creative in the sense of getting information legally," Dubinsky said. "For example, sometimes we do it under the guise of regular auditors."

The Internet has also helped: Fraud trackers regularly check the Internet for talk among possible offenders, who may be bragging about stealing money or corporate secrets.

Dubinsky said his targets are motivated by "greed, greed and more greed," but there are some psychological issues mixed in, too.

"My gut feeling is that a lot of these people are very insecure," he said. "One guy said all his friends had boats and country club memberships. I think that his own family was probably fine with it, but he was insecure."

For Dubinsky, business these days is booming. Between new public awareness of white-collar crime — thanks in part to high-profile cases like Enron (search) andWorldCom (search) — and the rarity of qualified investigators, his office is fielding more business locally and even expanding nationally.

Even though it is not cheap to do the job right, Dubinsky said his office has been getting calls "left and right."

An American Federation of Teachers (search) spokesman acknowledged that a forensic accounting investigation is expensive, but said it was worth it for the union. The national union took control of the Washington union after it was discovered that as much as $5 million might have been stolen from the local.

"While it was time-consuming and expensive, it was the kind of thing we felt was necessary," said Alex Wohl, the spokesman. Dubinsky helped turn "a very untransparent operation into a very transparent one."