OAKLAND, Calif. -- After failing one lie detector examination where he tried to implicate his estranged wife Nina Reiser’s boyfriend in her murder, Hans Reiser admitted to killing her and led police to her buried remains in exchange for a reduction in his conviction to second degree murder, sources told KTVU.

Defense attorney William Du Bois confirmed Tuesday that the deal involved a reduction in Reiser’s conviction from first degree to second – a difference which reduces his sentence from 25 years-to-life to 15 years-to-life. At an afternoon news conference, prosecutor Paul Hora said a deal had been struck for the second degree conviction, but that it had yet to be finalized.

Hans Reiser's sentencing, which had been schdeduled for Wednesday, would be continued, Hora added.

Another source disclosed to KTVU the lengthy process involved in reaching the deal.

Hans Reiser first told prosecutors a story that implicated Sean Sturgeon as the killer. Reiser claimed he had only helped bury the body. When he was asked to take a lie detector test while repeating the story, Reiser failed the test.

Hans Reiser then offered another story, in which he said he strangled Nina after the two fought. He was offered a deal for second degree murder, 15-to-life, and waived his appellate rights.

The prominent Bay Area software programmer, who had denied having anything to do with his estranged wife's disappearance, led police to her body on Monday.

The abrupt about-face came just two days before 44-year-old Reiser was due in court to face sentencing on a first-degree murder conviction returned by a jury in April.

The discovery late Monday afternoon came after Reiser, handcuffed to Du Bois, led police through Redwood Regional Park, defense attorney Richard Tamor said.

The body was found in a grave about four feet by four feet, Tamor said. Reiser did not have difficulty locating the spot, the attorney said: "He went right to it."

Tamor described Reiser's demeanor as "pensive, as anybody would be."

Police confirmed Tuesday the body had been identified as Nina Reiser. A source told KTVU that the remains were found in duffle bag stashed inside a garbage bag.

"This is a difficult scene to process. It's in a very rugged area," Alameda County Sheriff's spokesman J.D. Nelson said.

The ravine where the body was recovered was less than a mile from the house where Hans Reiser lived with his mother. The house is where Nina Reiser, 31, was last seen alive on Sept. 3, 2006, when she dropped off the couple's two children for a visit with their father.

In the weeks after Nina Reiser's disappearance, police led cadaver dogs into the same hills where the body was recovered Monday. Volunteers combed the area at the time and posted signs seeking information about the missing woman, who was active in a local Russian Orthodox church.

Reiser, known in programming circles for his ReiserFS file system, testified for several days in the six month trial and was scolded by the judge for arguing with the prosecutor.

Defense attorneys argued during the trial that there was no direct evidence linking their client to Nina Reiser's disappearance and suggested the woman might be living in Europe.

Prosecutors contended the circumstantial evidence against Reiser was strong: The two were involved in a bitter custody dispute, traces of her blood were found in his home and car and witnesses testified she would never have left her children.