How did Mollie Tibbetts die? Details explored ahead of Dateline on NBC 

Mollie Tibbetts was 20 when she disappeared during a routine evening jog on July 18, 2018, in the small town of Brooklyn, Iowa. She never came home. More than a month later, investigators found her body buried in a cornfield out in rural Poweshiek County. According to a report by KCRG-TV9, the Iowa State Medical Examiner confirmed on August 23, 2018, that she died from multiple sharp force injuries.

Her disappearance turned into a massive search effort. Local police, the FBI, and hundreds of volunteers poured time and energy into finding out what happened. There were tips and leads, but nothing solid until they reviewed security footage from the area where she went for the run. The investigators spotted a black Chevy Malibu driving close behind her in the footage.

The car led them to Cristhian Bahena Rivera. After being questioned, he took authorities to the field where Mollie was buried. He was later charged with first-degree murder, as per a report by The Gazette dated May 17, 2021.

Her case is now the focus of season 33, episode 22 of Dateline NBC, titled The Last Mile, airing on April 6, 2025, at 10/9c.

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Mollie Tibbetts was last spotted around 7:30 pm jogging in Brooklyn, Iowa, dressed in a pink top, dark shorts, and running shoes

On July 18, 2018, Mollie Tibbetts stepped out for her usual evening jog through the streets of Brooklyn, Iowa. She was staying at her boyfriend Dalton Jack's house while he was out of town for work.

That night, she wore a pink athletic top along with dark shorts and running shoes. Around 7:30 pm was the last time anyone saw her. Later that evening, Dalton opened a Snapchat from her. It showed up on his phone around 10, but the exact time when it was sent remains unknown, according to a report by Oxygen dated August 23, 2018.

The following day, Tibbetts failed to report to her job at a daycare center. When attempts to contact her were unsuccessful, her family reported her missing. As per an ABC News report dated July 27, 2018, Tibbetts' mother, Laura Calderwood, said:

“That is so out of Mollie's character, one, not to show up for work, two, not to let her employer know.”

Law enforcement agencies, including the FBI and Iowa Division of Criminal Investigation, launched an extensive multi-agency effort that would soon become one of the state's most high-profile missing person cases.

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A 34-day search, a breakthrough, and a confession

For over a month, authorities followed hundreds of leads, scoured rural areas, analyzed Mollie Tibbetts' digital footprint, and reviewed surveillance footage. According to The Gazette report dated May 17, 2021, investigators eventually obtained surveillance video showing a black Chevy Malibu trailing Tibbetts as she jogged through town.

The car was linked to 24-year-old Cristhian Bahena Rivera, a farmworker who lived nearby.

After being brought in for questioning, Rivera initially denied involvement but later admitted to approaching Mollie Tibbetts during her run. As per Moviedelic report dated April 5, 2025, he told investigators that when Tibbetts threatened to call the police, he became angry and claimed to have blacked out.

He further claimed that when he regained awareness, she was bleeding in the trunk of his car. Rivera led law enforcement to a secluded cornfield in rural Poweshiek County, where Tibbetts' body was recovered on August 21, 2018.

On August 23, 2018, the Iowa State Medical Examiner's Office officially confirmed the cause of death as multiple sharp force injuries, per The Gazette. Her death marked the end of a 34-day search and the beginning of legal proceedings that would stretch over the next three years.

In his initial court appearance, Rivera confessed to the killing. However, during his trial in May 2021, he introduced a new version of events. He claimed that two masked men had forced him to drive them around, killed Mollie Tibbetts, and made him dispose of the body. However, the prosecution argued that his account was inconsistent with earlier statements and unsupported by evidence.

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The trial and its broader impact

Rivera's trial began on May 17, 2021, in Scott County, Iowa, and concluded ten days later with a guilty verdict. On May 28, 2021, he was convicted of first-degree murder. He was sentenced to life in prison without the possibility of parole on August 30, 2021. As per an NPR report dated August 31, 2021, Judge Joel Yates stated during sentencing:

“Mr. Bahena Rivera, you and you alone forever changed the lives of those who loved Mollie Tibbetts.”

In the courtroom, Tibbetts' mother, Laura Calderwood, also delivered a victim impact statement. She said:

“Mollie was a young woman who simply wanted to go for a quiet run on the evening of July 18 and you chose to violently and sadistically end that life.”

The murder of Mollie Tibbetts drew national attention and fueled broader conversations on issues ranging from women's safety to immigration enforcement. As per a report by The Des Moines Register, dated August 22, 2018, authorities confirmed that Rivera was living in the U.S. illegally at the time of the crime. However, the focus of the investigation remained squarely on evidence linking him to Mollie Tibbetts' death.

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Watch season 33, episode 22 of Dateline NBC, airing on April 6, 2025, at 10/9c to learn more about Mollie Tibbetts' disappearance and murder.