The revelation came as prosecutors and defense lawyers have opened negotiations on a possible plea deal with the defendants that would avert the need for a trial.
Attorney Stephen Tapson, who represents defendant Nancy Garrido, told reporters outside court that he was there when his client and her husband, Phillip Garrido, were re-interviewed by detectives during the past month.
They acknowledged snatching Dugard, then 11, from a South Lake Tahoe street then answered dozens of questions about the years they spent with her and her two daughters fathered by defendant Phillip Garrido, Tapson said.
"Essentially they confessed to kidnapping and told where all the bodies are buried," Tapson said, characterizing the disclosures as "full confessions."
Nancy Garrido, 55, has pleaded not guilty to 18 felony counts that include false imprisonment, rape and child pornography. Her husband had been scheduled to enter a plea Monday, but his lawyer, Deputy Public Defender Susan Gellman, asked to postpone the arraignment until March 17.
Gellman would not confirm or deny Tapson's account. Tapson said the defendants have not worked out a plea deal, but prosecutors have proposed sentencing Phillip Garrido to 440 years in prison and his wife to more than 241 years.
The lawyer says Dugard was present during one of Nancy Garrido's interviews, apparently the first time the women had been face-to-face since the couple was arrested in 2009.