A US judge has ordered the unconditional release of Albert Woodfox, the country's longest-serving solitary confinement prisoner, who has spent 43 years in isolation behind bars in a Louisiana jail.
Woodfox (68) was placed in solitary confinement after he was accused of taking part in a riot that led to the death of prison guard Brent Miller in 1972.
He has always maintained his innocence, saying he was framed for the murder of the guard because of his membership of the Black Panther Party.
Now US judge James Brady has ordered that he be released from custody and not subjected to a third trial over the murder. Woodfox has been tried twice in the guard's death, but both convictions were overturned. The state is seeking to bring him to trial a third time. But Judge Brady said a third trial could not be fair.
The court order said several factors had contributed to his release.
"Mr Woodfox's age and poor health, his limited ability to present a defence at a third trial in light of the unavailability of witnesses, this court's lack of confidence in the state to provide a fair third trial, the prejudice done onto Mr Woodfox by spending over 40 years in solitary confinement, and finally the fact that Mr Woodfox has already been tried twice and would otherwise face his third trial for a crime that occurred over 40 years ago," the order reads.
Human rights experts have said that the amount of time he has spent in solitary amounts to torture.
A spokesman for the Louisiana attorney general said the state would appeal Judge Brady's ruling to the 5th US Circuit Court of Appeals "to make sure this murderer stays in prison and remains fully accountable for his actions".
However, Woodfox's lawyers were headed to St Francisville prison, where he is being held, to seek his release.
"We are thrilled that justice has come for our innocent friend," said Tory Pegram of the International Coalition to Free the Angola Three, who is working with Woodfox's lawyers on his release.
Woodfox was an inmate at the Angola prison in 1972 where he was serving time for armed robbery.
Woodfox and two other state prisoners became known as the 'Angola Three' due to their long stretches in solitary confinement at the Louisiana State Penitentiary. The prison lies next to a former slave plantation called Angola.
Woodfox is currently being held at a detention centre where he was placed in isolation ahead of his trial.
The other two men, Robert King and Herman Wallace, were released in 2001 and 2013 respectively.
Wallace, also convicted over Mr Miller's murder, died soon after his release pending a new trial. King's conviction was overturned.
King and Wallace were also initially imprisoned for armed robbery.
Woodfox and Wallace were involved with the Black Panthers, a militant black rights movement formed in 1966 for self-defence against police brutality and racism, which later embraced "revolutionary" struggle as a way of achieving black liberation.
Campaigners had long called for all three men to be released immediately.
Woodfox, Wallace and King consistently maintained they were imprisoned for crimes they did not commit, with convictions only obtained after mistrials.
King, who spent 29 years in solitary confinement, described his experience to the BBC in an interview three years ago.
He said he remained strong but it was "scary" to see how others crumbled through lack of human contact.
The three men have been the focus of a long-running international campaign.
Ms Pegram said she had spoken to Woodfox late on Monday and he was "excited and nervous".
Jasmine Heiss, a campaigner with Amnesty International USA, said the decision to release Woodfox was "a momentous step toward justice".