Mollie Tibbetts Died By 'Sharp Force Injuries': Autopsy

BROOKLYN, IOWA — Mollie Tibbetts was killed by "multiple sharp force injuries" and her death was ruled a homicide, according to preliminary autopsy results released by Iowa investigators Thursday. The 20-year-old University of Iowa student's body was found Tuesday in a cornfield about 15 miles from her hometown of Brooklyn after a weeks-long search that gained national attention.

Cristhian Bahena Rivera, 24, was arrested in Tibbetts' killing and charged with first-degree murder authorities said Tuesday. Rivera, a Mexican national, has been living in the country as an undocumented immigrant for about seven years.

Tibbetts was last seen July 18 while going for a jog. When she didn't show up for work the next day, authorities from multiple federal, state and local agencies mounted a massive search.

Tibbetts' family released the following statement on Wednesday:

Our hearts are broken.

On behalf of Mollie’s entire family, we thank all of those from around the world who have sent their thoughts and prayers for our girl. We know that many of you will join us as we continue to carry Mollie in our hearts forever.

At this time, our family asks that we be allowed the time to process our devastating loss and share our grief in private.

Again, thank you for the outpouring of love and support that has been shared in Mollie’s name. We remain forever grateful.

For more on the case, read: Mollie Tibbetts Killing Suspect Arrested: Police

At a news conference Tuesday, Division of Criminal Investigation Special Agent Rick Rahn said Rivera confessed to abducting and killing Tibbetts, then dumping her body in a cornfield near Guernsey, Iowa, about 15 minutes by car from Brooklyn. Rivera led investigators to the site Tuesday morning.

Rahn did not speculate about a motive.

"I can't speak about the motive. I can just tell you that it seemed that he followed her, seemed to be drawn to her on that particular day, for whatever reason he chose to abduct her," Rahn told reporters.

Rivera made his initial court appearance Wednesday in a rural Iowa courthouse. He was ordered jailed on a $5 million cash-only bond after a prosecutor said he was a danger to the community who was accused of a "heinous crime."

Rivera apparently presented out-of-state government identification and a matching Social Security card when he was hired to work at Yarrabee Farms, according to The Associated Press. That information was run through the Social Security Administration's employment-verification system and checked out, Dane Lang, the manager of the farm, said.

However, Yarrabee Farms on Wednesday said it hadn't run Rivera's name through the federal E-Verify system, the database of I-9 forms and tax records of employees across the country. Rivera also gave a false name, Yarrabee Farms said, according to the Des Moines Register.

Immigration and Customs Enforcement has lodged an immigration detainer for Rivera, which means the agency has probable cause to believe he is subject to deportation.

The Associated Press and Patch national writer Beth Dalbey contributed to this report.

Photo: Cristhian Bahena Rivera is escorted into the Poweshiek County Courthouse for his initial court appearance, Wednesday, Aug. 22, 2018, in Montezuma, Iowa. Rivera is charged with first-degree murder in the death of Mollie Tibbetts, who disappeared July 18 from Brooklyn, Iowa. Photo by Charlie Neibergall/Associated Press