For 35 years, Michael Whitney's girlfriend maintained the alibi that protected him from charges in a Wheaton woman's rape and slaying.
But on Tuesday, just hours after his grand jury indictment, Whitney told a judge he was ready to plead guilty.
The unusual turn of events came as DuPage County prosecutors announced Whitney's indictment on six counts of first-degree murder.
He is accused of raping and fatally stabbing his 28-year-old neighbor, Darlene Stack, in the early-morning hours of Aug. 18, 1976.
"I'm gonna plead guilty," Whitney told Judge Michael Cerne at a bond hearing, after he heard prosecutors outline the allegations against him.
Whitney, 58, has been serving a 60-year prison sentence for the murder of a 76-year-old Carol Stream man during a 1982 robbery.
But in 1976, authorities said, he was living with a girlfriend in the basement of the same Wheaton boardinghouse as Stack, an internist at Central DuPage Hospital.
Prosecutors and police said they've long suspected Whitney of the attack that left Stack with 33 stab wounds to the chest.
However, it wasn't until semen stains taken from the crime scene recently came up as a match for Whitney in a law enforcement database that they were able to connect him to the scene definitively, they said.
The revelation led Whitney's former girlfriend to recant prior statements and testimony that he was with her when the murder happened.
Prosecutors said they gave the girlfriend immunity in exchange for her cooperation; she will not be charged criminally.
"She indicated she lied all those years because she was not only in love with (Whitney) -- but she was also afraid of him," Assistant State's Attorney Joe Ruggiero said.
Stack moved into a room above Whitney at a boardinghouse on the 1400 block of North Stoddard Avenue, Ruggiero said, about three days before "the defendant brutally raped and murdered her."
A landlord found Stack's body later that afternoon. Ruggiero said it was a "horrendous" scene, with Stack gagged and her hands bound by cut up bedsheets.
Although the case went cold, Wheaton police reopened an investigation in 2005, which ultimately led to Whitney's indictment.
Ruggiero said the former girlfriend has given a videotaped statement and testified to the grand jury, saying she saw Whitney get out of bed naked and go upstairs in the boardinghouse the morning of Stack's murder.
After hearing muffled screams, the girlfriend told investigators Whitney returned saying, "We've got to get out of here."
The couple then drove to the DuPage River, where the girlfriend watched Whitney wipe blood off a knife and throw the weapon into the water, prosecutors said.
She also told investigators Whitney confessed to killing Stack during the drive.
Stack's older sister, Teri Stack, said by phone Tuesday that she was "very grateful" to see charges finally filed in the case.
"Before I die, I want to see my sister's case closed," she told the Daily Herald last year.
Whitney was due to be paroled next year from Big Muddy River Correctional Center in downstate Ina, where he has been serving a 60-year sentence for a 1982 armed robbery and murder in Carol Stream, records show.
On Oct. 10 of that year, prosecutors said, Whitney broke into the home of Cecil, 76, and Elizabeth Wallar, 69, who had been married for 50 years.
Whitney gained access by cutting through a window screen with a knife. He then cut up towels, which he used to bind and gag the couple while he stole their money and jewelry. Cecil Whitney might have tried to escape, and Whitney, prosecutors said, stabbed him in the chest.
Judge Cerne said he could not accept Whitney's guilty plea at a bond hearing, and appointed a public defender. Whitney's next court date is Aug. 22