MONTEZUMA, Iowa — The farmhand charged in the abduction and stabbing death of 20-year-old Mollie Tibbetts in Iowa has pleaded not guilty to first-degree murder.

Cristhian Bahena Rivera entered his plea Wednesday at the Poweshiek County Courthouse in Montezuma, Iowa.

Rivera is charged in the killing of Tibbetts, a University of Iowa student who disappeared while out for a run July 18 in Brooklyn, Iowa.

Investigators recovered her body a month later in a cornfield. A medical examiner has said Tibbetts was stabbed to death.

Rivera is a Mexican national who has been accused of being in the country illegally. The 24-year-old worked at a dairy farm a few miles from where Tibbetts disappeared.

He waived his right to be tried within 90 days. Trial is set for April 16.