BOULDER, Colo. - Prosecution is "unlikely" in the murder of JonBenet Ramsey, Boulder Police said Friday.
Police chief Mark Beckner issued a statement that said the investigation into the murder of the 6-year-old girl is currently considered a cold case.
"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."
Boulder police told 7NEWS that more than 150 DNA samples have been tested in the investigation. More than 140 people have been investigated as potential suspects, but none could be linked to the crime.
In 2008, JonBenet's parents, John and Patsy Ramsey, and JonBenet's brother, Burke, were exonerated by new DNA testing techniques, according to then-District Attorney Mary Lacy.
Lacy said the DNA testing pointed to a stranger.
However, a former district attorney lead investigator on the case wrote a book in 2012 that said the evidence in the case raised questions about whether an intruder was responsible.
"My theory definitely went against an intruder," said James Kolar. "There was strong physical evidence that discounted the intruder theory as it existed."
According to the Boulder Daily Camera, Kolar didn't say who he thinks killed JonBenet in his book called, "Foreign Faction: Who Really Kidnapped JonBenet?"
Kolar did say he is still hoping the case will be solved.
Patsy Ramsey died in 2006, 10 years after her daughter was murdered. She is buried next to her daughter in Georgia, where the Ramseys moved from Boulder.
John Ramsey remarried in 2011 -- five years after Patsy's death.