SALT LAKE CITY — A federal appeals court denied an accused cop killer's double jeopardy claim Tuesday.

Roberto Miramontes Roman asked the 10th Circuit Court of Appeals in Denver to stop authorities from prosecuting him in federal court after he was acquitted in state court.

The court concluded that the dual prosecutions would not violate the double jeopardy clause because legal precedent treats federal and state courts as independent sovereigns.

"Mr. Roman asks us to overrule these Supreme Court precedents. We cannot do that," according to a three-judge panel decision.

A jury in state court found Roman not guilty of aggravated murder but convicted him of tampering with evidence and possession of a dangerous weapon in connection with the Jan. 5, 2010, shooting that killed Millard County sheriff's deputy Josie Greathouse Fox.

Roman is serving a 10-year prison term.

A federal grand jury returned an 11-count indictment against Roman in September 2013, including a charge of intentionally killing a local law enforcement officer engaged in the performance of official duties.

Roman appealed to the 10th Circuit after U.S. District Judge David Nuffer ruled last year that regardless of whether the charges are based on the same conduct, they are being pursued under separate legal regimes and are not the same for purposes of double jeopardy.