Behind an anonymous-looking door on the fifth floor of the United States Secret Service headquarters, on H Street in Washington, D.C., is a small, windowless room known by the agents who work there as the Specimen Vault. Lining the walls are dozens of filing cabinets filled with narrow steel drawers containing scores of transparent plastic sleeves. In each sleeve is an individual note of U.S. currency—a single, five, ten, twenty, fifty, or hundred. The face value of the cash runs into the thousands, perhaps millions, of dollars. But despite the apparent wealth here, the money in the drawers is worthless.

The Specimen Vault is the reference library of the service's counterfeit investigators. It holds an example of every family of fake U.S. tender confiscated since the end of the 19th century. Most of the bills successfully spent—"passed," in law-enforcement jargon—were created decades ago by skilled artists familiar with the fine engraving and heavy machinery of the printing industry, career criminals who churned out hundreds of thousands of dollars at a time. However, the advent of desktop publishing has gradually changed the profile of counterfeiters, giving almost anyone with a scanner and a copy of Photoshop the means to print money. And while opportunistic bedroom forgers have made the crime more widespread, their operations are often small-scale and easy to detect. Few produce more than $10,000.

But in January 2005, the Secret Service field office in Los Angeles discovered a fake $100 bill of remarkably high quality. In the Specimen Vault four years later, Kelley Harris, supervisory counterfeit specialist of the Criminal Investigative Division, hands me a Ziploc bag containing 14 bills, which appear genuine. "Not bad," Harris concedes.

Despite the best efforts of the Secret Service, the printer behind these notes evaded capture for more than three years. By then, Albert Edward Talton, of Lawndale, California, was responsible for putting more than $7 million in phony currency into circulation. And he'd made much of it using supplies purchased from his local Staples.

Albert Talton, 44, is charming and soft-spoken, a big, fastidious man with a taste for expensive cars and high-end audio equipment. Born and raised in Southern California, he has been a criminal for most of his life. For 10 years he was in and out of jail, and in 2001 he was convicted of bank fraud and sentenced to five years in prison. Yet he also studied electrical engineering at California State University, Long Beach, and is a man of considerable ingenuity. In 1987, when Bose was manufacturing a new type of speaker system, Talton wanted to know how it worked. "I was amazed," he says from the Federal Correctional Institution in Lompoc, California. "How could they get that much bass out of a box the size of a shoe box?" So he bought himself a Bose setup from Circuit City for $2,500, went home, and took it apart. He figured out what the company's technicians had done and built his own version. This would not be Talton's last experiment in reverse engineering.