Story highlights Herman Wallace was in solitary confinement in Louisiana for more than 40 years

A judge ordered him released from prison Tuesday

Wallace claimed he was wrongly convicted in a prison guard's 1972 death

Wallace was one of the "Angola 3" inmates who protested conditions at the prison

Just days after he was released from a Louisiana prison for a murder he said he didn't commit, Herman Wallace has died, his legal team said Friday.

Wallace -- one of the "Angola 3" inmates who protested what they said were injustices at the Louisiana State Penitentiary at Angola -- died Friday morning at age 71 after a fight with liver cancer, his legal team said.

Wallace spent decades in solitary confinement after being convicted in 1974 of killing a guard at the Angola prison. He was released Tuesday after a judge vacated his murder conviction and sentence.

"Herman endured what very few of us can imagine, and he did it with grace, dignity, and empathy to the end," his legal team said in an e-mailed statement Friday.

"Although his freedom was much too brief, it meant the world to Herman to spend these last three days surrounded by the love of his family and friends," the team said. "One of the final things that Herman said to us was, 'I am free. I am free.'"

Ordering Wallace's release Tuesday, U.S. District Chief Judge Brian A. Jackson in Baton Rouge ruled that women were systematically excluded from the grand jury that indicted Wallace in the 1972 slaying of guard Brent Miller at Angola.

Wallace, who was serving an armed robbery sentence at the time of Miller's death, and other witnesses claimed Wallace was in another part of the prison when Miller was killed, his legal team said.

Jackson declined to address Wallace's other claims, including an allegation that the state knowingly used false testimony and withheld exculpatory evidence at trial.

Wallace was in solitary confinement at Angola until 2009, when he was moved to Hunt Correctional Center. He remained in solitary until he was diagnosed with terminal liver cancer this summer, according to one of his attorneys, Nick Trenticosta.

The "Angola 3" who protested conditions at Angola were Wallace, Albert Woodfox and Robert King.

Woodfox, like Wallace, was convicted in Miller's death. Before the guard's killing, Wallace and Woodfox tried to work to improve conditions at Angola, protesting bad sanitation and guard brutality, Wallace's lawyers said. They also tried to stop what they said were the rape of young men by fellow inmates, the lawyers said.

Wallace founded a Black Panther chapter at the prison. Both Wallace and Woodfox claimed they were targeted because of their activism as Black Panthers.

King, convicted in 1973 of killing a fellow inmate, was transferred to Angola just weeks after Miller was killed. Even so, he was investigated as a possible "conspirator" and put into solitary confinement alongside Wallace and Woodfox, according to the documentary "In the Land of the Free."

King's conviction was overturned in 2001, and he was freed.

Wallace and Woodfox, who remains in prison with appeals pending in his case, "endured very restrictive conditions, including periods of 23-hour cell confinement," according to Amnesty International USA.

As recently as this year, two death row inmates at Angola testified in court about being subjected to "indescribable" heat where they were held. The testimony was part of a lawsuit against the prison alleging that authorities placed inmates with pre-existing medical conditions at risk, the New Orleans Times Picayune reported.