BILLINGS, Mont. (AP) — A woman was arrested Monday on suspicion of killing a 6-year-old Lodge Grass girl.

The Big Horn County sheriff's office tells The Billings Gazette (http://bit.ly/1Ad2hHR ) that Kerstyn Oldbull was arrested in Hardin late Monday afternoon on a warrant that set her bail at $1 million.

A statement said Big Horn County deputies and FBI agents have been investigating since March 2. Kiomora Hogan's obituary said she died March 4.

No information on the cause of Kiomora's death was released.