An appeals court on Friday unanimously overturned the conviction against Albert Woodfox that has kept him in solitary confinement for more than four decades, bringing to an end a long, arduous quest for justice that spanned two prisons, alleged abuse by guards, and deteriorating health.

Calling the case "an important constitutional challenge," the Fifth Circuit Court of Appeals in Louisiana ruled 3-0 that Woodfox's 1998 retrial for a previous conviction was marred by racial discrimination and a number of other flaws.

"After more than 40 years of tirelessly pursuing justice through the courts, Albert Woodfox must now be given his freedom," said Tessa Murphy, USA Campaigner at Amnesty International, which has argued Woodfox's case in court for years. "The state should no longer impede justice but stand aside and allow this decision to stand."

The state may still appeal the decision, or re-indict Woodfox and try him in court yet again, which could blockade his freedom even longer, said Amnesty senior campaigner Jasmine Heiss.

"We of course continue to call for him to be immediately released," Heiss told Common Dreams. "If the state appeals, that could continue to delay the legal process by days or months or maybe even years."

Heiss said that outcome would be "unconscionable."

Woodfox, who was kept in shackles in court on Friday when the ruling was announced, remains in solitary, Heiss said. She added, "Tomorrow we will continue the struggle against this injustice."

As Jackie Sumell, a New Orleans activist and friend of Woodfox told the Times-Picayune, most of the witnesses in the case are deceased, and Woodfox has strong legal support.

The Times-Picayune writes:

Woodfox's possible release could take months or possibly years, depending on if the state files any number of appeals. But despite the "frustrating black hole" of not knowing exactly when he might be able to be released from custody, Sumell said Thursday's ruling was good news for those fighting the injustice Woodfox endured.

Woodfox's conviction has been overturned three times in the past. Federal courts ruled that the trial had violated his constitutional rights through racial discrimination, prosecutorial misconduct, inadequate defense, and suppression of exculpatory evidence.

But the state appealed each ruling, keeping him in prison—and solitary—for 42 years.

United Nations Special Rapporteur on Torture, Juan E. Méndez, in October 2013 called for Albert Woodfox’s immediate release from solitary confinement. "Four decades in solitary confinement can only be described as torture," he said.

Woodfox was convicted of second-degree murder of a prison guard in 1971, but the case was fraught with inconsistencies, lost evidence, and special favors paid between prison officials and inmates, as well as investigators and jury members. Woodfox and fellow inmate Herman Wallace were tried and convicted of the crime by an all-white jury within two hours. A third inmate, Robert King, was implicated but never charged. Over time, they became known as the Angola Three, a reference to the notorious Angola prison now known as Louisiana State Penitentiary.

While Wallace and King were eventually released, Woodfox remained in solitary confinement since the day of his conviction, confined to a small cell for 23 hours a day. He was transferred from Angola to the David Wade correctional center in unincorporated Claiborne Parish in 2010, but was immediately placed in closed-cell restriction there as well.

Wallace was set free on October 1, 2013, at age 71. He died the next day.

Both men continuously denied their involvement in the crime, maintaining that they were targeted and accused of the murder of Officer Brent Miller because of their activism in the Black Panther party, which they said angered the guards at Angola.

Woodfox "has been denied justice and detained for more than half of his life in a tiny cell after a conviction based on dubious evidence and testimonies," Murphy continued. "This injustice must end now."

Heiss added, "While it's not a perfect step for total justice, it's certainly one more step for Albert's freedom."