In a Fairfax, Virginia, courtroom, Matthew entered an Alford plea in connection with the 2005 case, which means he does not admit to a criminal act but acknowledges the prosecution has enough evidence to win the case.
Fairfax County Commonwealth's Attorney Raymond Morrogh said he considers Matthew's action equal to a guilty plea. Morrogh said the prosecution couldn't have stopped Matthew from entering an Alford plea and no deal was made with the defense to secure a lesser punishment.
"The defendant pled guilty to all of the charges, which means he faces the full range of punishment," he said.
Prosecutor praises 'fantastically brave' victim
In November, Matthew pleaded not guilty to the three charges tied to the September 24, 2005, incident in Fairfax, a city 20 miles west of Washington. The indictment claimed that he"did feloniously, willfully, deliberately, intentionally and with premeditation attempt to kill (the victim) in the commission of or subsequent to an abduction with the intent to defile."
Authorities say a 26-year-old woman there was returning from a grocery store when someone grabbed her from behind and sexually assaulted her.
"We saw her purse on the front sidewalk," said neighbor Stacey Simkins. "He had already dragged her behind our units to the dark pool area."
The FBI later indicated that "the offender was scared away by a passerby."
The victim flew from India, where she now lives, to testify. She plans to come back "to tell the judge how this has hurt her and affected her entire life, even to this day," Morrogh said.
"She wants a chance to speak up for herself," added the prosecutor. "I think she's a fantastically brave young woman."
Other alleged victim's mother 'reeling,' 'happy'
While it happened nine years earlier and 100 miles away, this case is inseparable from that of Hannah Graham -- the University of Virginia sophomore who disappeared
last fall and was later found dead.
A Fairfax County grand jury indicted Matthew in the sexual assault case two days after authorities found what turned out to be Graham's skull and bones on an abandoned property 8 miles from where she was last seen.
The 18-year-old went missing before dawn on September 13 after a night out in Charlottesville. Matthew was taken into custody 11 days later about 1,300 miles away on a beach in Galveston County, Texas.
In February, prosecutors said Matthew would be charged with first-degree murder
. Last month, he was served with a new indictment charging him with capital murder after Albemarle County Commonwealth's Attorney Denise Lunsford presented new forensic evidence to the grand jury.
Matthew has yet to stand trial in Graham's case. If convicted, he could be sentenced to death on the capital murder charge.
Harrington's mother, Gil, attended Wednesday's court proceedings in Fairfax which she said left her reeling. She expressed gratitude for the 2005 victim for speaking up, saying "I'm sure she didn't feel like the lucky one, but thank God" she came forward.
"I certainly want a day in court for my daughter," Gil Harrington told reporters. "But I am happy that it is very unlikely that this criminal will hurt anyone again."