Albert Woodfox, the last of three high-profile Louisiana prisoners known as the "Angola Three," could walk free within days after a federal judge ordered state officials to release him immediately. He has been in solitary confinement or isolation for 43 years.

US District Judge James Brady, the judge overseeing the closely watched human rights case, said Monday that the 68-year-old former Black Panther Party prison leader should be granted immediate freedom and not be tried again in the death of a prison guard stabbed to death during prison upheavals in 1972.

Amnesty International and the United Nations have condemned Woodfox's imprisonment as inhumane. Human rights advocates contend solitary confinement of the kind suffered by Woodfox is a form of torture.

Brady ordered Woodfox's unconditional release in a strongly-worded ruling. He cited doubt that the state could provide a "fair third trial"; the inmate's age and poor health; the unavailability of witnesses; "the prejudice done onto Mr. Woodfox by spending over forty years in solitary confinement," and "the very fact that Mr. Woodfox has already been tried twice."

Woodfox was accused, along with three other prisoners, in the stabbing death of Brent Miller, a 23-year-old guard at the Louisiana State Penitentiary at Angola. Miller was killed during a period of prison upheaval sparked by Black Panther activism aimed at improving conditions inside Louisiana's notorious prisons.

Woodfox was convicted twice at trial, but both convictions were overturned on the grounds of racial prejudice and lack of evidence.

Jasmine Heiss, a senior campaigner with Amnesty International USA, called Brady's ruling "a momentous step toward justice."

George Kendall and Carine Williams, his lawyers, were on their way to seek his release Monday night from the West Feliciana Parish Detention Center, where he has been placed in isolation awaiting his third trial.

Louisiana Attorney General James "Buddy" Caldwell has vowed to appeal the federal judge's order. The state has asked for an emergency stay of Brady's ruling from the 5th US Circuit Court of Appeals in New Orleans. The 5th Circuit was expected to rule soon — perhaps as early as Tuesday.

Tory Pegram of the International Coalition to Free the Angola 3, who is working with Woodfox's lawyers on his release, said she spoke with Woodfox late Monday.

"He's excited and nervous," she said.

Other prisoners in the Angola Three were Robert King and Herman Wallace. All three became members of the Black Panther Party while in prison, Pegram said. She said they were active in hunger strikes and work stoppages to protest conditions at the infamous prison. Pegram said their activism spurred changes that improved prison conditions.

Woodfox and Wallace were both serving armed robbery sentences and contended they were singled out for harsh treatment because of their political activism. Wallace died last year, days after a judge freed him and granted him a new trial. King was released in 2001 after his conviction in the death of a fellow inmate in 1973 was reversed.

Woodfox is in solitary confinement at a prison in St. Francisville, Louisiana, awaiting trial or his release.