Holloway was 18 when she went on the post-graduation trip with other students from Mountain Brook High School. She has not been seen alive since she left a nightclub with three men -- including Joran van der Sloot, identified by investigators as a suspect in her disappearance.
Holloway's father, Dave Holloway, told the Birmingham (Ala.) News the family hopes the ruling by Jefferson County Probate Judge Alan King "will bring some closure" but he expects it will be some days before it hits home.
"I have been preparing myself for this day for the last 6 1/2 years," he told the newspaper.
The FBI is treating the matter as a homicide but no charges have been filed against van der Sloot, 24, who pleaded guilty Wednesday to killing Stephany Flores, 21, in Lima. Dave Holloway told the newspaper he hopes the court in Peru will sentence van der Sloot to 30 years, as prosecutors are requesting.
"I hope the Flores family will finally get justice," he said.
Dave Holloway said he petitioned to have his daughter declared dead because it could eventually help the criminal investigation and because the family needs a death certificate so his son can access her college fund to pay for his senior year in college, the newspaper reported.
2014: The Year in Music [PHOTOS]