Investigators also revealed publicly a double life in which they say Paige, using the name "Carrie," offered escort services. Using her cell phone records, police have interviewed some of her former clients.
Birgfeld kept an office in town for her to house a business she called Grand River Acupuncture, but officials say she was not licensed to practice. Tenants of the building told the Denver Post that she often would enter the office in off-hours with different men.
The news that their daughter was allegedly working as an escort surprised her family and friends, who universally described Birgfeld as a devoted single mother, albeit one who was juggling many jobs to support her family.
"As a dad, if I had known it, I would have probably urged her away from it," Frank Birgfeld said. "One on moral grounds and two, because it was dangerous."
But he also said that his daughter, an attractive young woman, was merely doing what she had to in order to raise her family on her own. And, he added, they would never let her double life distract them from finding their daughter.
"These searchers are absolutely relentless, they say, 'We're going to search until we find her,'" Frank Birgfeld said. "There's almost a grit of their teeth when they say it."