An Alabama judge signed an order Thursday declaring Natalee Holloway legally dead, attorneys for her family said.
Probate Judge Alan King signed the order after an afternoon hearing in Jefferson County court in Birmingham.
Holloway was 18 when she was last seen in the early hours of May 30, 2005, leaving a nightclub on the Caribbean island of Aruba with Joran van der Sloot and two other men. No one was charged in her disappearance, and her body has never been found.
On Wednesday, van der Sloot -- who was detained twice in connection with Holloway's disappearance but never charged -- confessed in a Lima court to murdering a 21-year-old Peruvian woman five years after Holloway went missing.
In 2005, the Alabama teenager was visiting the island with about 100 classmates to celebrate their graduation from Mountain Brook High School in suburban Birmingham.
Dave Holloway, Natalee's father, filed a petition to declare his daughter dead six years later, in June.
He was present at Thursday's hearing, as was his ex-wife, Beth Holloway. She has opposed the move to declare Beth dead, pointing to a lack of evidence indicating his daughter is deceased and saying in a September statement that she "will always hope and pray for Natalee's safe return."
On Thursday, she told reporters while leaving the courtroom that she was upset by the judge's decision.
"Natalee's father wanted to see this through, and of course it makes me very sad," said Beth Holloway, who now works with groups and families of missing children.
Dave Holloway previously testified at a hearing that his daughter has not been seen in more than five years and no body has been found, White said.
In the September hearing, King ruled the petition could go forward, according to CNN affiliate WBRC.
At that time, King ruled that a notice of presumption of death must be published in a local newspaper for two successive weeks, followed by a 12-week time frame to submit any evidence the teen is still alive, WBRC said. Barring any such evidence, the judge would then be able to declare her dead.
Dave Holloway filed the petition to achieve closure for his family, his attorney Mark White said, but also to resolve his daughter's estate. She is still listed as a participant and beneficiary on her father's health insurance, and there is a small college fund in her name.
Van der Sloot pleaded guilty Wednesday to all the charges against him in the killing of a Peruvian woman in 2010.
The 24-year-old Dutch national faces a sentence of 30 years.
Investigators believe van der Sloot killed Stephany Flores after she found something related to the Holloway case on van der Sloot's computer as she visited with him in his hotel room.
Van der Sloot also faces possible extradition to the United States. In June 2010, a federal grand jury in Alabama indicted him on charges of wire fraud and extortion after allegations surfaced that he tried to extort $250,000 from Holloway's mother. Van der Sloot offered to provide what turned out to be bogus information about the whereabouts of Natalee Holloway's remains in exchange for the money, according to the indictment.
He was allegedly given a total of $25,000, and authorities believe he used that money to travel to Peru and participate in a poker tournament, where he met Flores.
Peggy Sanford, a spokeswoman for the U.S. Attorney's office for north Alabama, said that there's no timetable as to when federal authorities will seek to bring van der Sloot to the United States for prosecution.
"We want Joran van der Sloot to face the charges here, and we are prepared to try him as soon as we can get him to the United States," Sanford said. "Right now, we don't know when that will be."