Allegations that Mark Hofmann compiled a possible hit list in coded prison letters are without substance and may be timed to coincide with the release of a new book on the confessed bomber's crimes, his lawyer says.

The Salt Lake Tribune and KSL-TV quoted unnamed law enforcement officials as saying FBI cryptologists in Washington found that Hofmann's letters contained biographical information about Board of Pardons members Victoria Palacios and Gary Webster and documents examiner George Throckmorton.Hofmann pleaded guilty to second-degree murder in the Oct. 15, 1985, pipe-bomb slayings of Steven F. Christensen, 30, and Kathleen Sheets, 50, and to theft by deception for his dealings in fraudulent historical documents.

Throckmorton exposed many of Hofmann's documents as forgeries, and Palacios and Webster recommended in January that Hofmann be kept in prison for the rest of his life.

At issue now are some 30 letters Hofmann wrote to his wife, Doralee, who recently turned them over to Mike George, an investigator with the Salt Lake County attorney's office.

Utah Department of Corrections spokesman Juan Benavidez confirmed Friday that Hofmann is the target of an investigation, but he declined to comment on the nature of the probe.

Cal Clegg, special agent with the FBI's Salt Lake City bureau, and U.S. Attorney Brent Ward would neither confirm nor deny their agencies' involvement in the investigation.

KSL and the Tribune said the coded letters gave some confirmation to statements by prison informants to authorities that Hofmann intended to have certain people harmed or killed.

But Hofmann's attorney, Ronald Yengich, charged that the allegations were made by unnamed law enforcement sources, based on the tips of anonymous prison "snitches."

"Once again, the United States of America relies on their most formidable weapon - the undisclosed, confidential source - for these types of allegations," Yengich said. "I've looked at the letters, or some of them, and I didn't see anything untoward. Apparently, they (the FBI) didn't find any overt threats."

Yengich also speculated that the new controversy surrounding his client may be related to the arrival in area bookstores of "The Mormon Murders," the second of three books written on the Hofmann case.

"It seems to me that we have two interesting facts," Yengich said. "Number one, we have this week the release of a book on the Hofmann case that apparently people involved in the investigation cooperated in. So maybe it would be interesting for there to be a new Hofmann story the week the book is released.

"The second thing, it just seems to me that they have no bona fide claims that he (Hofmann) has done anything wrong. It's an easy excuse to use to send him from the state of Utah to a federal institution," Yengich said.

The Tribune quoted sources as saying state and federal officials were considering sending Hofmann to a federal maximum security prison, such as the facility in Marion, Ill.

Authorities doubt that Hofmann has the resources to hire people to commit murder. But they said they are taking the threats seriously, KSL reported.

Hofmann's wife was unaware of the purported codes and willingly turned over the letters to investigators, officials said. Copies were then sent to the FBI laboratory in Washington, D.C.

Hofmann refused to provide the key to break the code, and, when told he might be sent to a federal facility if he didn't cooperate, "He said something like, `Maybe that would be best, then my family could forget about me,' " one source was quoted by The Tribune as saying.

The FBI lab broke the code about three weeks ago. The letters contained what one source described as "sketchy biographical data" about the purported victims.

"Stuff like their names, their addresses, maiden names, I think even the names of children," one law enforcement official said. "It's like he was compiling information, a little bit at a time. It's a little bit like microfilm, just kind of putting it away for future reference."