HELENA, Mont. (AP) – The U.S. Supreme Court has declined to take up the petition of an FBI agent seeking immunity against allegations that he failed to properly investigate the deaths of two men because they were Native Americans.

That means the lawsuit filed by the families of the deceased men against Matthew Oravec can go on. The families of Steven Bearcrane and Robert "Bugsy" Springfield claim Oravec conducted only the most cursory investigations the deaths of the Crow tribal members.

Bearcrane, 23, died Feb. 2, 2005, in a shooting on a ranch on the Crow Reservation. Springfield, 48, who lived in Casper, Wyo., died on a bow-hunting trip in the Bighorn Mountains. He disappeared Sept. 19, 2004, and hunters found his remains in October 2005.

The families claim that Native American victims are regularly denied adequate investigation and prosecution of their cases. They sued the FBI and Oravec’s supervisor, but a federal judge ruled in 2010 they only had sufficient standing to claim that Oravec was motivated by racial animosity, and dismissed the claims against the FBI and the supervisor.

Oravec appealed the decision to 9th U.S. Circuit Court of Appeals. The appellate court ruled in January 2012 that Oravec could be sued because the families sufficiently claimed that Oravec had provided Bearcrane’s relatives with fewer investigatory services than he would have provided a non-Indian victim’s family.

The appeals court ruled the families had not made similarly sufficient allegations in Springfield’s death, but said they could amend their lawsuit.

Oravec then filed a petition with the Supreme Court seeking to overturn the appellate court’s ruling. The Supreme Court on Jan. 14 declined to take up the petition.

The New York Times first reported on the Supreme Court’s decision.

Former South Dakota U.S. Attorney Steven K. Mullins declined to prosecute Bearcrane’s alleged shooter based on information from a federal investigation. The case had been referred to Mullins’ office to avoid a possible conflict because a relative of Bearcrane-Cole worked in the office of Montana’s U.S. attorney.

The lawsuit also alleges Springfield died under suspicious circumstances and that the FBI failed to investigate his disappearance.

The case now goes back to U.S. Magistrate Judge Carolyn Ostby, who has scheduled a conference for Feb. 27.