Louisiana attorneys are set to ask a federal appeals court Wednesday to block the release of longtime state inmate Albert Woodfox and allow prosecutors to try him a third time in the 1972 death of a prison guard.

Woodfox is the last still-incarcerated member of a group that supporters dubbed the "Angola Three" for their decades-long stays in isolation at the Louisiana Penitentiary at Angola and other state prisons.

U.S. District Judge James Brady in Baton Rouge ordered Woodfox's "immediate" release in June and took the extraordinary step of barring a third trial for the 68-year-old inmate in the death of prison guard Brent Miller.

Brady noted that 43 years have passed since the crime, key witnesses have died and there is no physical evidence linking him to the stabbing.

The state fought the decision and the 5th Circuit extended a stay keeping Woodfox jailed during the state's appeal.

The other two members of the "Angola Three" were Herman Wallace, who died in October 2013, just days after a judge granted him a new trial in Miller's death, and Robert King, who was released in 2001 after his conviction in the death of a fellow inmate was overturned.

Woodfox's previous convictions in Miller's death were overturned for reasons including racial bias in selecting a grand jury foreman and juror misconduct.

The state disputes human rights groups' contentions that Woodfox was held in "solitary confinement," saying that while in prison Woodfox was able to talk to other inmates, have visitors, watch television through the bars of his cell and leave the cell daily for an hour.

After he was indicted a third time in Miller's death, Woodfox was transferred to the West Feliciana Parish Detention Center to await trial.