The U.S. Attorney's Office filed charges on Tuesday against three people who allegedly helped three defendants charged with killing a man on the Wind River Indian Reservation last year.

Garrett Revere Jr., Chrissy Bigeagle and Will Wallowingbull were charged with being accessories after the fact in the killing of Jared Dean Little Whiteman, according to the criminal information documents filed in U.S. District Court.

Revere, Bigeagle and Wallowingbull, according to the documents, "did relieve, comfort and assist the offenders, Susan Lynn Chippewa, James Leo Whiteplume, and Byron Robert Spoonhunter, in order to hinder and prevent the apprehension, trial and punishment of Chippewa, Whiteplume and Spoonhunter."

If convicted, the three new defendants could face up to 15 years imprisonment, fines up to $250,000, and three years supervised release.

The criminal information documents did not identify how Revere, Bigeagle and Wallowingbull helped the other defendants.

According to federal court documents, Little Whiteman in June was allegedly taken from his grandmother's house to a trailer, where Chippewa stabbed him and the other two defendants took the body and buried him.

FBI and Bureau of Indian Affairs officers exhumed and identified the body.

But law enforcement had not been able to locate the white Kia SUV allegedly used to carry Little Whiteman's body to the burial site.

Last month, the SUV was found near Denver. The investigation of the van could take up to eight weeks, according to prosecutors.

The three lead defendants were scheduled to go on trial in federal court in Casper this week.

But U.S. District Court Judge Scott Skavdahl reset the trial date to April 27.