The Navajo Nation sued the federal government and the city of Winslow in March on behalf of Loreal Tsingine’s daughter.
Authorities say Tsingine posed a threat to now former Winslow police Officer Austin Shipley when he killed her in March 2016.
Navajo officials say he should have used non-lethal force. The tribe alleged violations of her equal protection rights in its claim against the Justice Department.
The department has said it couldn’t prove beyond a reasonable doubt that Shipley willfully used excessive force.
It asked a judge this week to dismiss the federal defendants, saying they’re immune from lawsuits.