Bismarck, N.D. ? The government had the right to prosecute American Indian activist Leonard Peltier for crimes that occurred on a South Dakota reservation, a federal appeals court has ruled.

Peltier is serving two consecutive life sentences for the deaths of two FBI agents during a 1975 standoff near Oglala, S.D., on the Pine Ridge Indian Reservation. He has filed numerous appeals since he was convicted by a jury in Fargo in 1977.

In the latest appeal, Peltier and his lawyers argued that federal courts have no jurisdiction over Indian land.

U.S. District Judge Ralph Erickson ruled last summer that the government has the right to prosecute and imprison anyone who kills federal agents, no matter where the crimes occur.

Peltier appealed that decision to the 8th U.S. Circuit Court of Appeals. The court upheld Erickson’s ruling Friday.

“Killing a federal officer engaged in his or her official duties affects the federal government’s ability to execute its laws and is thus an offense that the United States can punish,” wrote Judge Morris Arnold in the decision.

Barry Bachrach, Peltier’s lawyer, said Friday afternoon that he hadn’t yet told his client about the latest decision.

“We are disappointed, and we’re just going to keep moving forward with the issues to correct this injustice,” he said.

“Leonard Peltier has had his day in court many times over, and his convictions and sentences have been upheld again and again,” U.S. Atty. Drew Wrigley said. “This judgment should be viewed for what it is: final.”

The Pine Ridge shootout left three people dead amid battles between federal agents and the American Indian Movement in the 1970s.

FBI agents Ronald Williams and Jack Coler were shot in the head at point-blank range. The Justice Department concluded that an FBI sniper killed AIM member Joseph Stuntz.

Peltier has claimed the FBI framed him, which the agency denies. His supporters said he was treated unfairly because of his political activism.