On Dec. 26, 1996, JonBenet's parents, John and Patsy Ramsey, woke up to find their daughter missing and a ransom note saying she had been kidnapped.
Hours later, the girl body was found in a basement room in her parents' home, strangled to death.
Investigators have not made any arrests in the case. Boulder, Colo., Police chief Mark Beckner said the case is currently considered cold., KMGH-TV, Denver, reported.
"The case is still open, but is not actively being investigated and there are no new leads," Beckner said. "While we believe at this point it is unlikely there will ever be a prosecution, the Boulder Police Department still holds out some hope that one day the district attorney and the Boulder Police Department will be able to put together a case worthy of presenting to a jury."
In October, it was revealed that in 1999, a grand jury voted to indict John and Patsy Ramsey on charges of child abuse resulting in death and accessory to a crime. The charges were later tossed by then-District Attorney Alex Hunter because he didn't think he could prove the parents were guilty.