A defense attorney is seeking an address book, recordings and other information in an attempt to challenge the integrity of an undercover operative key to a multistate investigation into illegal artifact trafficking.

Walter Bugden, a Salt Lake City lawyer, is representing Durango, Colo., antique dealers Carl Lavern Crites and Marie Crites and two other indicted co-defendants rounded up during a June 10 raid that federal agents coordinated across Utah, Colorado, Arizona and New Mexico.

While requesting information on a witness's reliability is standard for defense, Bugden said his discovery request is tailored to a civilian investigator identified in court papers as the "Source" who went undercover for a 2½-year federal sting operation.

"It's not exactly blind man's bluff," Bugden said Tuesday. "We are trying to ascertain whether he has credibility problems."

Along with other specific information about the conduct of the investigation, Bugden is seeking the address book that the FBI cited in an investigation report dated Nov. 19, 2006, the same month federal agents signed up the Source, previously identified in The Salt Lake Tribune as a Utah resident and former antiquities dealer Ted Gardiner.

The defense motion names Gardiner, and seeks information specific to a Sept. 14, 2008, excavation of a prehistoric grave on public land.

The search warrant affidavit accompanying the Crites indictment, which also included co-defendants Richard Bourret of Durango and Steven Shrader of Santa Fe, N.M., says the men and the Source dug into an ancient Puebloan burial mound with shovels and rakes.

They were under surveillance. The Source wore an audio-video transmitter and a team of U.S. Bureau of Land Management special agents was observing from nearby.

As the three piled dirt onto a blue plastic tarp, they uncovered a human skull. Bourret picked up the skull and put it back in the hole. Court documents say Crites lamented a lost opportunity, saying he "wished that fella had still been intact, the skeleton, I mean."

Shrader shot himself to death in Illinois on June 18. James Redd, a Blanding physician also indicted on a felony charge in June, had killed himself a week earlier.

His wife, Jeanne, and daughter Jericca, also of Blanding, pleaded guilty to multiple felonies last summer and forfeited their artifact collections in a plea deal that kept them out of prison.

On Aug. 19, the Criteses voluntarily surrendered an extensive collection of artifacts assembled over 50 years. Court papers said the collection includes prayer sticks, fire sticks, a bone scraper and "cloud blowers," the ceremonial pipes that Hopi and their ancestors used in prayer offerings. It took several moving trucks to hold the collection.

Bugden and federal prosecutors negotiated the handover, but that didn't necessarily indicate a coming plea deal, Melodie Rydalch, spokeswoman for the U.S. Attorney for Utah, has said.

Bugden seeks complete copies of any service agreements Gardiner entered with the FBI, Bureau of Land Management, the Internal Revenue Service or any other state or federal agency. He also wants information about any criminal activity involving Gardiner federal or state authorities were aware of regardless of whether there were prosecutions.

Authorities are "presenting this person as just a good citizen. We're trying to find out if that's true," Bugden said. "Generally a cooperating witness has a strong incentive, motive or bias to become a cooperator. It generally doesn't happen as a moral revelation. It's more often based on self-interest."

Gardiner declined to comment for this story.

Officials have acknowledged a 2005 DUI arrest of Gardiner that was reduced to reckless driving and a misuse of federal funds they say has been resolved.