Mollie Tibbetts murder: Inmate to testify in defense motion for new trial Cristhian Bahena Rivera's defense is asking for a new trial based on two new statements that name another person involved in the murder. Author: Denise Hnytka Updated: 7:41 PM CDT July 12, 2021 POWESHIEK COUNTY, Iowa — A judge in Poweshiek County, Iowa will hear testimony from an inmate who claims he heard another story about the murder of Mollie Tibbetts. That new evidence is part of the motion for a new trial filed last week. Tibbetts was found stabbed to death in a cornfield back in August 2018. Farm worker Cristhian Bahena Rivera was charged with her murder after he led investigators to her body. A jury convicted him of first degree murder in May 2021.