Denver ? Attorneys for jailed American Indian advocate Leonard Peltier told a federal appeals court Friday the government is denying him a parole hearing on the unproven claim that he ambushed two FBI agents before gunning them down 28 years ago.

Peltier, 59, will have been in prison twice as long as required by federal guidelines if no hearing is held until 2008 as decreed by the U.S. Parole Commission, attorney Barry Bachrach said.

The commission departed from federal parole guidelines in 1996 after concluding Peltier fired the fatal shots during a 1975 gun battle on South Dakota’s Pine Ridge Indian Reservation — even though that was never proven in court, Bachrach said.

“The decision must be reversed if the facts are incorrect and unsupported by the record,” he told a three-judge panel of the 10th U.S. Circuit Court of Appeals.

The judges took the case under advisement.

U.S. Atty. Eric Melgren, of Wichita, Kan., said the commission made clear that Peltier should not be paroled even if he wasn’t the shooter.

“Whether he was involved directly or he was aiding and abetting, he was involved in the premeditated, cold-blooded murder of two federal agents,” Melgren said.

The commission based its finding on the exhaustive court record, which includes numerous unsuccessful appeals of Peltier’s conviction and sentence, Melgren said.

“If another hearing were granted, the commission would view this again in largely the same way,” he said.

Demonstrators rally for the release of Leonard Peltier on the steps of the federal courthouse in Denver. Attorneys for Peltier, an American Indian advocate imprisoned for killing two FBI agents 28 years ago in South Dakota, asked a federal appeals court Friday to grant him a parole hearing.

Peltier, 59, was convicted in the 1975 slayings of FBI agents Ronald Williams and Jack Coler on the sprawling reservation. A shootout erupted when the agents, searching for a robbery suspect, drove on the property of a family that Peltier’s lawyers say had sought protection from the American Indian Movement during conflicts on the reservation.

The agents were shot in the head at close range and their bodies left on a dirt road. Two men were acquitted in the case and a fourth freed for lack of evidence.

Judge Stephen Anderson peppered Melgren with questions about the reasons given for delaying a parole hearing.

“Isn’t it troubling that the commission relied on unestablished facts?” Anderson asked.

However, Anderson also asked Bachrach what he would do if a hearing is held and parole is denied. The judge speculated the attorneys might then use other strategies to win parole for Peltier.

The Leonard Peltier Defense Committee is based in Lawrence, Kan.

The case has become a rallying point for American Indian and human rights advocates, who believe Peltier is a political prisoner. After the hearing, more than 200 supporters rallied outside the courthouse, with American Indians singing and beating drums. Many carried American Indian Movement banners and “Free Peltier” signs.

Longtime AIM leader Russell Means told the crowd support from the public helped sustain Peltier.

“Leonard represents all Indian people of the Western Hemisphere and the institutionalized racism that permeates the entire American society against my Indian people, my ancestors and my way of life,” Means said.

President Clinton denied Peltier clemency in 2000, a decision supporters blamed on a protest by 500 FBI agents and their families outside the White House.

The slayings occurred at a time when tension was high among political factions on the Pine Ridge reservation and between Indian activists and federal authorities.

In 1973, AIM members clashed with reservation officials and held federal agents at bay for 71 days in a siege at the village of Wounded Knee. The village was the site of an 1890 massacre by the cavalry in which an estimated 300 Indians died.