ABC News May 26, 2021

Defendant says Mollie Tibbetts was killed by 2 masked mystery men, in stunning claim

WATCH: Accused killer makes stunning claim in Mollie Tibbetts trial

The trial of a Mexican national for the murder of Mollie Tibbetts took a wild twist on Wednesday when the defendant dropped a bombshell from the witness stand -- claiming he was kidnapped by two masked and armed men, who forced him to drive to where the 20-year-old University of Iowa student was jogging and that one of them killed her and put her body in his car's trunk.

In a surprise move, Cristhian Bahena Rivera, 26, testified in his own defense in a Davenport, Iowa, courtroom and detailed the never-before-heard scenario of the 2018 slaying that sent shockwaves across the nation.

Bahena Rivera testified that on July 18, 2018, the day Tibbetts went missing, he emerged from taking a shower at the trailer where he lived and found two strangers in his living room.

"They were both wearing sweaters and their faces (were) covered," Bahena Rivera said through a Spanish interpreter. "One of them was bigger and a little bit fatter. The other one was about my stature."

He testified that the larger man had a gun and the other had a knife.

Kelsey Kremer/Pool via AP
Cristhian Bahena Rivera enters the courtroom following a break, May 24, 2021, in the Scott County Courthouse, in Davenport, Iowa. Bahena Rivera is on trial after being charged with first degree murder in the death of Mollie Tibbetts in July 2018.

"They said I should not do anything stupid and everything was going to be OK," testified Bahena Rivera, an undocumented immigrant who said that at age 17, he paid a coyote human trafficker money his family scraped together to smuggle him across the Rio Grande on an inflatable raft packed with people.

He said the men whispered to each other for a "long while" and then ordered him to go with them to his car, a black Chevrolet Malibu.

'We saw a person jogging'

Bahena Rivera said the bigger man got in the backseat and the smaller man sat next to him in the front. He claimed they ordered him to drive into the nearby town of Brooklyn, Iowa.

"They told me to drive straight. One of them said to the other one something about someone running," Bahena Rivera testified.

He said they drove through town and out to rural 385th Avenue, where they "saw a person jogging." He said he now realizes the jogger was Tibbetts.

"We just continued driving, and then they asked me to turn around," said Bahena Rivera.

MORE: Trial for man accused of killing Mollie Tibbetts: Key takeaways from Day 5

He said that as they drove, the two assailants crouched down in their seats as if they didn't want to be seen.

Bahena Rivera claimed he drove past Tibbetts three or four times. He said the last time they drove past her she was jogging in the opposite direction back into town.

"We continued forward, and they asked me to turn and go back," he said.

Tibbetts' boyfriend had alibi

He said before they reached Tibbetts, he was ordered to stop, and the smaller man got out of the car and headed in the direction of Tibbetts. He claimed the other man remained in the back seat and they waited for 10 to 12 minutes.

Bahena Rivera claimed that as they waited, he heard the man in the back seat whispering to himself.

Court TV
Cristhian Bahena Rivera listens to court proceedings as he takes the witness stand during his trial, May 26, 2021, in the Scott County Courthouse in Davenport, Iowa. Bahena Rivera is on trial for the 2018 stabbing death of Mollie Tibbetts, a University of Iowa student.

"What I heard him say was, 'Come on, Jack,'" Bahena Rivera testified.

The testimony came a day after the defense called Dalton Jack, Tibbetts' boyfriend who had initially testified for the prosecution, back to the witness stand. Jack had admitted he had an affair with a woman and that Tibbetts had found out and threatened to leave him about a month before her death.

Defense attorneys Jennifer Frese and her husband, Chad Frese, have insinuated throughout the trial that Jack was involved in Tibbetts' killing, but prosecutors said Jack had a solid alibi: He testified that he was working on a bridge construction project in Dubuque, Iowa, about 140 miles from Brooklyn, the day Tibbetts went missing and that he had nothing to do with her death.

Bahena Rivera testified that he did not know Jack and that he wasn't referring to him as the one the assailant was talking about.

Kelsey Kremer/The Des Moines Register via AP, Pool
Dalton Jack, Mollie Tibbetts' boyfriend, testifies for a second time during Cristhian Bahena Rivera's trial, May 25, 2021, in the Scott County Courthouse in Davenport, Iowa.

He testified that the smaller man returned to the car and asked him to drive forward about 300 meters, or 1,000 feet. He said they stopped again and the smaller man asked him to shut the car off and give him the keys.

He said the man got out, and he heard his trunk open.

"I just heard a movement in the car and the trunk close," Bahena Rivera testified.

MORE: Key takeaways from trial of Iowa farmworker charged with Mollie Tibbetts' murder

He said the smaller man got back in the car and ordered him to drive straight. He claimed they drove several miles at a high rate of speed.

Bahena Rivera testified that they drove to a white house next to a cornfield and that he was ordered to drive down a dirt road alongside the cornfield and stop.

Defendant says assailants threatened to harm his family

He said the men took his keys and cellphone, and then threatened to harm his ex-girlfriend, Iris Gamboa, the mother of his 5-year-old daughter.

"One of them tells me not to say anything about what happened, that they knew Iris and that they knew my daughter," Bahena Rivera said. "That if I said something that they would take care of them."

MORE: Key takeaways from Day 2 of trial for accused killer of University of Iowa student Mollie Tibbetts

He said the two men left him alone in the cornfield, walked back to the road and vanished. He said he has never seen them since.

"I got out of the car," he testified. "I obviously knew there was something in the trunk."

Kelsey Kremer/Pool via AP
Cristhian Bahena Rivera gestures towards a monitor as he testifies during his trial, May 26, 2021, in the Scott County Courthouse in Davenport, Iowa. Bahena Rivera is on trial for the 2018 stabbing death of Mollie Tibbetts, a University of Iowa student.

He said he looked in the trunk and found the body of a woman he now recognizes as Tibbetts.

"At the beginning, I saw a little bit of movement. Then there was no movement," he testified.

'I put her in the cornfield'

Bahena Rivera claimed he thought for a few minutes before he removed Tibbetts' body from the trunk.

"I picked her up, and then I put her in the cornfield," he testified.

Under direct questioning from Jennifer Frese, Bahena Rivera said he put leaves over Tibbetts' body not to conceal her, but to prevent her from "being exposed to the sun."

Court TV
Defense attorney Jennifer Frese listnes during the trial of Cristhian Bahena Rivera at the Scott County Courthouse in Davenport, Iowa, May 26, 2021. Rivera is charged with first-degree murder in the death of Mollie Tibbetts.

He said he was "scared" to call the police and feared the two men would make good on their promise to harm his family.

Bahena Rivera testified he found his keys and cellphone in the trunk of his car along with Tibbetts' phone, Fitbit and earbuds. He said he left Tibbetts' property on the side of a road as he drove home.

MORE: Key takeaways from trial of Iowa farmworker charged with Mollie Tibbetts' murder

Bahena Rivera largely contradicted testimony from former West Liberty and Iowa City police officer Pamela Romero, who testified that he implicated himself in Tibbett's death during an interview she conducted. Romero claimed Bahena Rivera confessed to seeing Tibbetts running, stopped his car and ran after her. She said Bahena Rivera claimed Tibbetts threatened to call the police on him and that he got angry and they fought.

MORE: Key takeaways from trial of Iowa farmworker charged with Mollie Tibbetts' murder

Romero said Bahena Rivera claimed he "blacked out" and didn't remember how Tibbetts, who was stabbed repeatedly, ended up in his trunk. Bahena Rivera, according to investigators, allegedly claimed he drove Tibbetts to the cornfield and ditched her body on his own.

'You stabbed Mollie Tibbetts, isn't that right?'

On cross-examination, prosecutor Scott Brown grilled Bahena Rivera, asking if he was the "only one" who led police to the cornfield where Tibbetts' badly decomposed body was found on Aug. 21, 2018, a month after she went missing.

Kelsey Kremer/Pool via AP
Assistant Iowa Attorney General Scott Brown and Poweshiek County Attorney Bart Klaver speak to each other during the cross examination of a witness during Cristhian Bahena Rivera's trial, May 26, 2021, in the Scott County Courthouse, in Davenport, Iowa. Bahena Rivera is on trial after being charged with first degree murder in the 2018 death of Mollie Tibbetts.

"You never mentioned two other men, did you?" Brown asked Bahena Rivera of the interview with Romero and other investigators, which lasted 11 hours.

Bahena Rivera replied, "No."

"You told Pamela Romero that you got angry at Ms. Tibbetts, didn't you?" Brown asked.

The defendant responded, "I think so."

An apparently exasperated Brown then said, "You stabbed Mollie Tibbetts, isn't that right? You're the one who did that, isn't that true?"

"No," Bahena Rivera answered.

The defense rested its case Wednesday afternoon. Closing arguments are scheduled for Thursday morning.