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The man convicted in the 2018 death of Mollie Tibbetts, a University of Iowa student, was sentenced to life in prison Monday, three years after she disappeared while on an evening run. 

Judge Joel Yates sentenced Cristhian Bahena Rivera to life without the possibility of parole, the mandatory sentence for first-degree murder in Iowa, which does not have the death penalty. The 27-year-old former farmhand, who testified that he came to the U.S. illegally from Mexico as a teenager, has been jailed since his arrest in August 2018.

"Based upon the facts and circumstances of this case, it is very well deserved," prosecutor Scott Brown said of the life sentence.

Tibbetts, 20, vanished while running on a rural road outside her hometown of Brooklyn, Iowa on July 18, 2018. Investigators were led to Bahena Rivera after surveillance video from a homeowner appeared to show his Chevy Malibu repeatedly driving past Tibbetts as she was jogging. 

MOLLIE TIBBETTS MURDER TRIAL: JURY FINDS CHRISTIAN BAHENA RIVERA GUILTY

Cristhian Bahena Rivera listens to proceedings during his sentencing Monday at the Poweshiek County Courthouse in Montezuma, Iowa. He was sentenced to life in prison for the stabbing death of college student Mollie Tibbetts. (AP Photo/Charlie Neibergall, pool)

He eventually led investigators to Tibbetts' body, which was found in a cornfield a month after her disappearance. She had been stabbed several times. 

Bahena Rivera said he approached Tibbetts because he found her attractive and that she threatened to call the police. Prosecutors suggested he had a sexual motive, saying Tibbetts was wearing only socks and a sports bra and that her legs were spread when her body was found. They built their case around the surveillance video, his partial confession and DNA evidence of Tibbetts' blood in his car's trunk.

Tibbetts' mother, Laura Calderwood, addressed Bahena Rivera in a victim impact statement read by a representative to the court.

MOLLIE TIBBETTS MURDER: DEFENSE SAYS MISSING 11-YEAR-OLD BOY, SEX TRAFFICKING RING LINKED TO CASE

"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," she wrote.

She told Bahena Rivera that the case caused Hispanic workers to flee the area and prevented life events like her daughter's boyfriend from proposing to her.

Laura Calderwood, mother of Mollie Tibbetts, leaves the courtroom after a sentencing hearing for Cristhian Bahena Rivera. (AP Photo/Charlie Neibergall, pool)

"Because of your actions Mr. Rivera, I will never get to see my daughter become a mother," Calderwood said.

The case elicited anger over illegal immigration and was mentioned by then-President Trump in a video posted online. He said the "incredible young woman, is now permanently separated from her family" while blasting U.S. immigration laws. Some members of Tibbetts' family pushed back on the narrative. 

During his trial, Bahena Rivera surprised everyone when he testified that he was kidnapped from his trailer by two masked men at gunpoint. He said they forced him to drive and that they Tibbetts and told him to dispose of her body. 

He said they threatened to kill his former girlfriend and young daughter if he didn't keep quiet. Defense attorneys also tried to cast suspicion on Tibbetts' boyfriend.

In this September 2016 file photo provided by Kim Calderwood, Mollie Tibbetts poses for a picture during homecoming festivities at BGM High School in her hometown of Brooklyn, Iowa. (Kim Calderwood via AP, File)

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The case took another turn after Bahena Rivera's conviction when two people came forward and said a 21-year-old man had confessed to killing Tibbetts. Yates delayed sentencing so defense lawyers could investigate. 

In a request for a new trial, they attempted to link Tibbetts' death to a young woman's report of having been kidnapped and sexually assaulted at a home used for sex trafficking and the disappearance of an 11-year-old boy from the same county. Investigators did not find a link between Tibbetts' death and the missing boy.

Yates denied the motion, saying much of the evidence presented was known to them before the guilty verdict. Defense lawyers said they plan to appeal the sentence. 

The Associated Press contributed to this report.