From the Wikipedia page 
Mark William Hofmann (born December 7, 1954) is an American counterfeiter, forger and convicted murderer.
In 1980, Hofmann said that he had found a 17th-century King James Bible with a folded paper gummed inside. The document seemed to be the transcript that Joseph Smith's scribe Martin Harris had presented to Charles Anthon, a Columbia classics professor, in 1828. According to the Mormon scripture Joseph Smith–History, the transcript and its unusual reformed Egyptian characters were copied by Smith from the golden plates from which he translated the Book of Mormon.
Hofmann constructed his version to fit Anthon's description of the document, and its discovery made Hofmann's reputation. Dean Jessee, an editor of Joseph Smith's papers and the best-known expert on handwriting and old documents in the Historical Department of the LDS Church, concluded that the document was a Joseph Smith holograph. The LDS Church announced the discovery of the Anthon Transcript in April and purchased it from Hofmann for more than $20,000. Appraised by the LDS Church for $25,000, it was purchased on October 13 in exchange for several artifacts the church owned in duplicate, including a $5 gold Mormon coin, Deseret banknotes, and a first edition of the Book of Mormon. Assuming the document to be genuine, prominent Mormon academic Hugh Nibley predicted that the discovery promised "as good a test as we'll ever get of the authenticity of the Book of Mormon" because he thought the paper might be translated. Zoology professor Barry Fell soon after claimed to have decoded the text.
Hofmann promptly dropped out of school and went into business as a dealer in rare books. He soon fabricated other historically significant documents and became noted among LDS Church history buffs for his "discoveries" of previously unknown materials pertaining to the Latter Day Saint movement. These deceived not only members of the First Presidency — notably Gordon B. Hinckley, then the de facto president of the church due to the poor health of more senior leaders — but also document experts and distinguished historians. According to Richard and Joan Ostling, Hofmann was by this time a "closet apostate" motivated not only by greed but also by "the desire to embarrass the church by undermining church history."