DNA recovered from a chain at the site of an Occupy Wall Street protest in March has been matched with DNA linked to the unsolved killing of a Juilliard student in 2004, law enforcement officials familiar with the case said on Tuesday.

The student, Sarah Fox, 21, disappeared while on a jog in Inwood Hill Park in May 2004, and her naked body was found in the park almost a week later surrounded by yellow tulip petals. The DNA on the chain from the New York protest, the officials said, was matched with DNA found on her portable compact disc player, which was found in the park several days after her body was discovered.

Investigators were seeking to determine the significance of the DNA match. One law enforcement official said it was unclear who might have touched both the CD player and the chain and why, noting that it was possible that the person who did so might not have been the killer.

“Whether it’s a friend or the bad guy, we have to find out,” the official said.

The chain was used in March to prop open an emergency exit door at a subway station as part of an Occupy Wall Street action to allow passengers to ride free.