WASHINGTON Native American rights activist Leonard Peltier, who has been in prison for nearly 50 years, is turning 80 on Thursday and Amnesty International USA is appealing to Joe Biden to finally release him before his presidency comes to an end.

Peltier was recently denied parole and compassionate release by the US Parole Commission and the Bureau of Prisons (BOP) respectively, reads a Sept. 4 letter to Biden from Paul OBrien, the groups executive director.

As President of the United States, you have the opportunity to rectify a case that has long troubled human rights advocates and Indigenous Peoples worldwide, OBrien wrote.

Peltier has been in prison since the U.S. government put him there in the 1970s. He was convicted for the murder of two FBI agents during a 1975 shootout on Pine Ridge Reservation in South Dakota, and was given two consecutive life sentences.

But there was never evidence that Peltier killed anyone. His trial featured astounding levels of misconduct , including federal prosecutors hiding exculpatory evidence and abruptly changing their charge to aiding and abetting after someone found the evidence theyd hidden.

The FBI never did figure out who killed those agents; the federal prosecutor in Peltiers case, Lynn Crooks, later admitted as much . But the U.S. government needed someone to go to prison. Peltier a member of the American Indian Movement, a grassroots Indigenous activist group the FBI was targeting was one of dozens of people present at the shootout, and was the only person left to go after. He was separated from his co-defendants, all of whom had been acquitted on grounds of self-defense, and was found guilty.

As the years have rolled by, Peltiers imprisonment has drawn outcry from U.S. politicians, tribal leaders, celebrities and international human rights leaders including Pope Frances, the Dalai Lama and Nelson Mandela. His parole process has violated international standards , drawing unusual condemnation from United Nations human rights legal experts, who in 2022 called his prolonged imprisonment arbitrary and simply the result of his being Native American.

Peltier has maintained his innocence all these years. The FBI has said he should never be released, offering outdated and incorrect statements to justify his imprisonment. Peltier was up for parole earlier this year, but was denied.

He is considered Americas longest-serving political prisoner .