Not long ago, Salt Lake City book dealer Ken Sanders, owner of Ken Sanders Rare Books, almost bought a hand-written Brigham Young calling card. He placed a bid on it — for $1,200 — and then realized he had seen an item just like it a couple of years earlier when his store hosted a Mark Hofmann symposium called "Authentic Fakes." Later, he found out that the owner of the card had had dealings with Hofmann in the 1980s.

Sanders tells this story on himself to point out how, even though Hofmann has been locked up for more than 18 years, some of his forgeries are still in circulation, and people continue to be fooled. "Sometimes they're sold innocently, sometimes not so innocently," said Sanders, who serves on the security committee of the Antiquarian Booksellers Association of America.

"You couldn't sell a Mormon document for a decade after Hofmann" pleaded guilty, Sanders says. Even now, any document Hofmann may have touched, or whose pedigree can't be traced back to before Hofmann, is suspect, he says.

But the Americana documents are another matter. Just how many Hofmanns are still being traded isn't known. A sheet of paper found under Hofmann's jail cell mattress in 1988 listed 129 documents and signatures he hadn't mentioned during 1987 plea-bargained interviews with prosecutors. But since honesty wasn't Hofmann's strong suit, no one knows if the list is accurate.

Jennifer Larson, a Rochester, N.Y., book dealer who has researched Hofmann documents, says, "I know fairly surely of several dozen" Hofmann forgeries still in circulation. The lessons learned from 1986 have been lost on document dealers, collectors, librarians and scholars, she says. "Not many people are interested in the non-Mormon forgeries that may be unidentified and unlocated," she said. "And even fewer are interested in the wider problems of authentication that Hofmann's success should have exposed.

"If anything," she said, "I think the problem is now worse than it was in the 1980s. . . . The Internet now offers an easy, efficient, anonymous method of offering questionable merchandise to a very wide audience; while many buyers might be suspicious, all a forger or a thief has to find is one."

Both forensic expert Throckmorton and collector Ashworth say they have run across rare document dealers who have sold items that have been pointed out as Hofmann forgeries. Throckmorton remembers a Daniel Boone letter sold by a Denver auction house; he told the dealer the letter was forged, but the response, says Throckmorton, was "We don't care." The dealer explained, "We never guarantee it's authentic. We just guarantee we'll give them their money back if they're not satisfied."