The U.S. Parole Commission has denied release for Leonard Peltier, a 79-year-old member of the American Indian Movement convicted of murdering two FBI agents during a shootout on the Pine Ridge Reservation in South Dakota.

Peltier, who has maintained his innocence during his 47 years in prison, appeared for a parole hearing last month at the federal complex in Coleman, Fla., northwest of Orlando. His next opportunity for parole is set for June 2039, said Kevin Sharp, his attorney.

In 1973, Native Americans led by the American Indian Movement occupied Wounded Knee, S.D., over Indian rights issues in a historic standoff with federal authorities. In 1974, two AIM leaders, Dennis Banks and Russell Means, went on trial in federal court in St. Paul. The trial ended when U.S. District Judge Fred Nichol dismissed the charges, citing government conduct.

The following year, Special FBI Agents Jack Coler and Ronald Williams were shot while driving separate cars in pursuit of a robbery suspect on the reservation. A gunman then shot and killed the agents at close range. The FBI said that gunman was Peltier. His supporters have long held that prosecutors only showed that he was present at the shootout, not that he fired the fatal shots.

“Our position is that you’ve got a conviction on a seriously flawed set of facts,” Sharp said in an interview last month. “You have a conviction that is seriously tainted with investigation and prosecutorial misconduct, yet Leonard has spent over half of his life in prison. Any additional incarceration is just retribution. It serves no purpose toward any idea of justice. You also have got a nearly 80-year-old man who spent nearly 50 years in prison. He has a serious health condition. The prison cannot take care of his health needs. They got their pound of flesh. It’s time to end this.”

FBI Director Christopher Wray submitted a statement urging the commission to reject Peltier’s parole.

“We must never forget or put aside that Peltier intentionally murdered these two young men and has never expressed remorse for his ruthless actions. … Granting parole for Peltier would only serve to diminish the brutality of his crime and further the suffering of the surviving families of Coler and Williams, as well as the larger FBI family.”

Responding to the Parole Commission’s decision on Tuesday, Paul O’Brien, executive director of human rights group Amnesty International USA, called on President Joe Biden to grant Peltier clemency, calling his continued incarceration a “human rights travesty.”

“President Biden should grant him clemency and release him immediately,” O’Brien said. “Not only are there ongoing, unresolved concerns about the fairness of his trial, he has spent nearly 50 years in prison, is approaching 80 years old and suffers from several chronic health problems.”

Natalie Bara, president of the FBI Agents Association, commended the decision for Peltier, who she referred to as an “unremorseful murderer.”

“We believe this decision upholds justice for our fallen colleagues and their families,” said Bara.