The nation has been transfixed with the case of missing Iowa woman Mollie Tibbetts, who went missing July 18 while out for a run in Brooklyn, IA.

Sadly, police announced Tuesday afternoon that they have found what they believe to be the body of Tibbetts in a nearby field.

Police hold a press conference on the discovery of Mollie Tibbetts' remains. https://t.co/WwstQWYg7d
https://t.co/fN21a9ccMA

— Fox News (@FoxNews) August 21, 2018

Police have also detained a suspect in the case. Twenty-four-year-old Christian Rivera is believed to be in the country illegally.

BREAKING: Cristhian Bahena Rivera, 24, an undocumented immigrant, has been arrested for the death and disappearance of Mollie Tibbetts. pic.twitter.com/dndgyUieOp

— Bill Schammert (@BillSchammert) August 21, 2018

A suspect in connection with Mollie Tibbetts’ murder is in custody and has been identified as a 24-year-old man in the U.S. illegally, investigators announced at a news conference Tuesday.

Christian Rivera was charged with first-degree murder in Tibbetts’ death, officials confirmed Tuesday afternoon.

Authorities said that Rivera, of the rural Poweshiek County area, is being held on a federal immigration detainer. He’s believed to have been in the area for four to seven years.

 The body of Tibbetts, a 20-year-old University of Iowa student, was found Tuesday, her father and two sources confirmed to Fox News. She was last seen around 7:30 p.m. on July 18 when she was running around a neighborhood in Brooklyn.