But Wednesday night, New York news outlets were reporting that the purported link could have been the result of a laboratory error.
The New York Times reported that a source said the DNA appeared to have come from "a Police Department employee who works with the Office of the Chief Medical Examiner."
The New York Post and New York Daily News filed similar reports, with the Post quoting a source as saying it was "highly improbable" that there was a link.
Earlier in the day, the initial report of a DNA connection brought only a guarded response from Fox's uncle, Isaac Porter of Millville.
The family had discussed the development and was confident that "in due time, something substantial will pop up," Porter said.
But, he added, "basically, we're holding back. We're not getting involved and saying much at this time."
Fox's body was found surrounded by yellow tulip petals during a search by 90 volunteers from South Jersey, who with the help of sniffer dogs scoured the 196-acre Inwood Hill Park. They had flocked to New York after initial police efforts to find Fox were unsuccessful.
Fox, 5-foot-2 and 110 pounds, was probably jogging through the park. An autopsy showed that her larynx had been crushed, a sign of strangulation, but was inconclusive about whether she was sexually assaulted.
No arrest was ever made, although Dimitry Sheinman, who lived near the park, was named as a person of interest by authorities after he claimed to have a vision of the body and allegedly described unpublished details.
Investigators were unsure if the petals simply blew off a tree or were purposefully scattered around her.
The New York Police Department did not respond Wednesday to requests to confirm or elaborate on the latest reported developments.
Fox grew up in Pennsauken with her mother, Lorraine, and sister, Samantha. Her father, a Vietnam veteran, had died years before of cancer.
During her high school years she studied acting at the Southern New Jersey Academy of the Performing Arts, now known as the School of Performing Arts. It's based at the Gloucester County Institute of Technology in Sewell.
About 350 people, including Juilliard faculty and students, made the trip from New York to attend June 2004 services at a Pennsauken funeral home.
Among those who paid tribute to her was Michael Walls, a founder of the Gloucester County academy's drama program. He recalled a young woman who could "find good in everything" and who was "unique, wonderful, and full of promise."
Contact staff writer Peter Mucha at 215-854-4342 or email@example.com.
Inquirer staff writer Darran Simon contributed to this article.