Lawyers for the man charged with killing University of Iowa student Mollie Tibbetts are asking a judge to throw out evidence discovered during a faulty interrogation, including the victim's body.
A court hearing is scheduled Wednesday to consider the matter.
Tibbetts disappeared in July 2018 while out for a run in Brooklyn, Iowa.
Farm worker Cristhian Bahena Rivera allegedly implicated himself in her death during a lengthy interrogation one month later. The 25-year-old eventually led detectives to her body in a cornfield.
A prosecutor has acknowledged that officers mistakenly failed to read Rivera all of his legal rights during that interrogation.
Rivera's lawyers argue that means his statements and evidence related to the body must be suppressed. But prosecutors say the body would have inevitably been discovered.
Rivera is scheduled to stand trial for first-degree murder in February.