The U.S. Attorney's Office has filed new charges against the defendants in a stabbing death on the Wind River Indian Reservation last year.

In the second superseding indictment, prosecutors added to the original charges that, if convicted, already carried life sentences for Susan Lynn Chippewa, Jaymes Leo Whiteplume and Byron Robert Spoonhunter for their involvement in the death of Jared Dean Little Whiteman.

In September, Chippewa, Whiteplume and Spoonhunber were charged with aiding and abetting first degree murder. They pleaded not guilty in U.S. District Court in Casper in January.

But prosecutors filed a new indictment last week.

Besides the original charge of aiding and abetting first degree murder, all three were charged with first degree felony murder, punishable by life imprisonment.

Whiteplume also was charged with kidnapping resulting in death and carrying a firearm during a crime of violence. The kidnapping charge is punishable by life imprisonment. The firearms charge automatically carries a punishment of not less than seven years in prison.

The defendants are scheduled for their arraignments in federal court before U.S. Magistrate Judge Michael Shickich in Casper at 3 p.m. Thursday.

The second superseding indictment did not explain what lead to the additional charges.

However, the van used to carry Little Whiteman's body was found in Colorado in February, and is being processed for evidence.

Last week, three more defendants were charged for being accessories after the fact.

Chippewa, Whiteplume and Spoonhunter remain in custody. Their trial is scheduled to begin in Casper on April 27.