Authorities in Iowa say theyve arrested an undocumented immigrant in connection with the disappearance of Mollie Tibbetts.

Cristhian Bahena Rivera, 24, has admitted to abducting the 20-year-old college student, according to Rick Rahn, of the Iowa Division of Criminal Investigation. Rivera was taken into custody Tuesday morning and is facing a first-degree murder charge.

Rahn said a vehicle driven by Rivera was seen on surveillance video in the Brooklyn, Iowa, area on the day Tibbetts disappeared. When questioned by police, Rivera not only confessed to being involved with Tibbetts disappearance but also led investigators to her body, according to Rahn.

For whatever reason, he chose to abduct her, Rahn said.

During police questioning, Rivera said he approached Tibbetts when he saw her jogging.

He ... ran behind her and then at one point tells us Mollie grabbed ahold of her phone and said, You need to leave me alone or I am going to call the police, Rahn said. Then she took off running. He, in turn, chased her down and then he tells us that at some point in time he blacks out and then comes too near an intersection, which we believe is where he placed Mollie.

Rahn said Tibbetts body had been covered with cornstalks.