A judge has dismissed child pornography charges against a former suspect in the killing of US child beauty queen JonBenet Ramsey.
Mr Karr was extradited to the US from Thailand in August
Prosecutors in Santa Rosa, California, said they did not have enough evidence to proceed against John Mark Karr.
Mr Karr was recently investigated over the 1996 death of JonBenet Ramsey after he claimed to have killed her, but DNA tests cleared him of the crime.
Mr Karr, 41, was extradited to the US from Thailand in August.
Judge Rene Chouteau has now ordered Mr Karr's immediate release.
Mr Karr's arrest in Thailand sparked hopes in the US that one of the most infamous crimes of recent years might finally be solved.
The former teacher had said he was with six-year-old JonBenet Ramsey when she died, but that her death was an accident.
However, the case against him was dropped after forensic tests found that his DNA did not match that discovered at the scene of the crime.
Mr Karr remained in police custody, following a request that he be taken to California to face child pornography charges dating back to 2001.
JonBenet's body was found in the cellar of her family home after her parents had reported her missing on 26 December 1996.
She had been garrotted with a cord and her skull had been fractured.
JonBenet's family, who later moved to Atlanta, Georgia, fought for years to clear their names of persistent accusations that they were involved in the death of their daughter.