Lawyers for Georgia death row inmate Troy Anthony Davis have filed two appeals to the US Supreme Court.
The legal team is challening recent rulings from federal courts in both Savannah and Atlanta.
A Savannah judge ruled, Davis didn't prove his clear innocence at a hearing last year.
An Atlanta appeals panel later ruled, it didn't have the authority to hear Davis' appeals against that ruling.
Davis' sister Martina Correria says, the main issue is finding a court that will be fair.
"There were specific things that the lower court was supposed to answer that they didn't answer," Correia says. "And coming back to Savannah we actually were at a disadvantage because things were stacked against us."
Georgia condemned Davis for the 1989 killing of Savannah police officer Marc Macphail.
The case has been before several courts, but his supporters are still pushing for a new trial.
"I don't feel that that's the best appeal and the best chance that we could have had," Correia says. "I think that the Supreme Court should step in and give us an opportunity before a fair and impartial court."
A spokesman for the MacPhail family would not comment on the latest appeal.
Marc MacPhail, Jr., the slain officer's son who has spoken for the family, says that he has not yet read the appeal, which was filed late on Friday.
In the past, however, MacPhail has noted that Davis has had many chances to make his case.
"Here we are, 21 years later, still waiting," he said during the hearing in Savannah in 2010.
That hearing attracted Davis supporters from around the country and lots of news media.
The case has become an international cause for opponents of the death penalty.