(Reuters) – The accused killer of Iowa college student Mollie Tibbetts, whose disappearance produced national headlines, pleaded not guilty to first-degree murder at a court appearance on Wednesday.

Cristhian Bahena Rivera, a 24-year-old farm worker from Mexico accused of stabbing 20-year-old Tibbetts, appeared in a black-and-white striped jumpsuit at his arraignment in Poweshiek County Courthouse in Montezuma, Iowa.

“Mr. Rivera pleads not guilty,” his lawyer Chad Frese told the judge as Rivera listened through black headphones to a translator.

District Court Judge Joel Yates set his trial for April 16. Rivera was ordered held on $5 million bail at a previous court appearance.

Tibbetts, a University of Iowa student, vanished while jogging on July 18, and her body was found about a month later in a field near Brooklyn, Iowa.

Law enforcement officials told reporters that Rivera was in the country illegally. His defense lawyer has said in a court filing that Rivera had legal status.

The case further fueled a national debate over illegal immigration and crime, with U.S. President Donald Trump saying Tibbetts’ death was a result of weak immigration laws.

In an opinion piece for the Des Moines Register earlier this month, Tibbetts’ father, Rob Tibbetts, called on politicians not to “distort” her death to advance views “she believed were profoundly racist.”

(Reporting by Barbara Goldberg in New York; Editing by Joseph Ax and Bill Berkrot)