Last July, Mark Hofmann wrote a letter from prison. Written in what is apparently his real handwriting these days — a backward slant of printed letters — it includes an admission by Utah's infamous forger. A rare penny soon to be auctioned in California, Hofmann told a family member, is a fake he created with "an electroplating process."

Hofmann's life sentence in 1987 for the pipe-bomb murders of two Utahns put an end to his forgery career. But evidence of his wide-ranging deceptions — historical documents, signatures, a poem by Emily Dickinson — continue to surface. The rare Lincoln penny (estimated value "$25,000-up," according to the auction house) may be one recent example. If so, it has caught coin collectors and the U.S. Secret Service off guard.

The penny, a 1959-D whose reverse side includes the wheat stalk design that was discontinued in 1958, was investigated last spring by the Counterfeit Division of the U.S. Secret Service, which declared the coin authentic. The testing included examination under a 200-power optical scanning electron micrograph, according to Coin World magazine.

"The coin it talks about is one of my forgeries," Hofmann wrote to his family in the July 24 letter, which included a copy of the magazine article. "It is struck from dies I made with an electroplating process."

Ira Goldberg, co-owner of Ira and Larry Goldberg Coins and Collectibles Inc. of Beverly Hills, Calif., which is set to auction the penny on Sept. 23, doesn't believe Hofmann is telling the truth in the letter. "Just because he said he made it doesn't mean by any stretch of the imagination he did. Here's a guy sitting in prison reading Coin World. . . . He's a known liar. I take it with a grain of salt."

"If it were electroplating, you'd see a seam," says Goldberg. It would also be detectable by measuring the coin's specific weight and gravity, he says. "I think he's trying to get publicity."

Salt Lake rare book collector Ken Sanders says he was shown the letter by Hofmann's ex-wife, Doralee. The coin, Sanders says, is just one of three Hofmann forgeries that have recently been discovered, including a new Daniel Boone forgery. Sanders has organized a symposium called "Genuine Fakes: The Forgeries of Mark Hofmann," for Sept. 13 and 14 at Ken Sanders Rare Books, 268 S. 200 East.

Sanders has corresponded with an East Coast physician named Anthony Marks, who recently discovered that his prize possession — an original Daniel Boone document he purchased 18 years ago for $6,050— is a Hofmann original. Marks shared with Sanders a letter he received this summer from Hofmann, written from prison.

"I forged several Boone items," Hofmann wrote. "But if I remember correctly, I spiced your single-page document up with the mention of powder and lead (spelled 'led')."

"I never intended my forgeries to have money-losing victims," Hofmann wrote. "I'm sorry that they did."

The Boone document was authenticated in 1993 by one of the world's leading handwriting experts, Charles Hamilton.

According to LDS Church historian Richard Turley, who will be one of the presenters at the upcoming "Genuine Fakes" symposium, the church has discovered 446 Hofmann forgeries in its collections. At the symposium, "I plan to strongly advocate that other institutions and individuals with Hofmann materials clearly identify them as such," Turley says. "Failure to do so only enhances the likelihood that others will be victimized by Hofmann's crimes."

Although he is most widely known for his forgeries of historical documents, Hofmann also is believed to have made counterfeit coins.

Utah author Linda Sillitoe, who co-authored "Salamander," the first of several books written about Hofmann, says she was told by his friends that he dabbled in coin tricks and forgeries as a child and teenager. When he was still in grade school he sold a friend a nickel with a buffalo on both the front and back (when the friend got it home and took it out of the plastic, it turned out to have been two nickels glued together). Later, as a teenager, he sold at least one coin whose mint mark he had altered, Sillitoe says.

California coin collector Larry Choate, who bought the 1959 penny for $27,500, says he has wondered for years if it is authentic. Although it might seem that he would have a lot to lose if the penny is a fake, Choate says that under federal counterfeit laws he would actually be refunded all his money if Hofmann is telling the truth.

Choate says he will try to contact Hofmann. "If he has visiting rights, I'd actually get on a plane and meet him personally."