For more than two years after their 20-year-old daughter Rena died, Rose and Keith Nguyen urged authorities in Utah County to prosecute her boyfriend.

They wanted recognition from the criminal justice system that their daughter took her own life only after Caleb Aidan Rees, knowing she was in crisis, yelled at her as she cried and left a loaded handgun in a room with her, then walked away.

The Nguyens hired attorneys and brought on an expert to help make their case for taking the rare step of holding someone else accountable for a suicide, saying their daughter, a Brigham Young University student from northern California, was a victim of domestic abuse.

Almost four years later, Rees pleaded guilty to a third-degree felony count of manslaughter in April, along with other drug and weapons charges. And on Friday, in an emotional court hearing, a judge in Provo’s 4th District Court ordered him to serve up to 20 years in prison.

Rena Nguyen’s parents say they want the outcome to deter others who would do the same to a romantic partner. They also hope other authorities in Utah and beyond will take a fresh look at similar cases already closed without any criminal charges being filed.

“I believe we must do more than just teach victims to escape abuse,” Keith Nguyen told the judge on Friday. “We must use every tool under the law to deter anyone who even considers harming another person.”

The Nguyens’ attorney, Richard Lambert, said it’s the first case he knows of in the United States “in which a domestic abuser has driven someone to take their own life, has been held accountable for that action.”

He sees parallels to a case in Scotland where a man is serving eight years in prison after prosecutors argued his wife’s suicide followed physical and emotional abuse in their 18-month marriage.

In court, prosecutors played part of a phone recording Rena Nguyen had secretly taken in Orem in October 2021 that captured her interactions with Rees in the hours leading up to her death.

Judge Sean Petersen called the recording “nothing short of horrific” on Friday before ordering Rees to four consecutive terms of up to five years in prison.

“It is not normal or accepted behavior — the repeated threats, demeaning statements, and the ridicule, Mr. Rees, that you heaped upon Rena,” the judge said. He went on to say that “it gives me a lot of pause about your future relationships and the safety of the public.”

Prosecutors had alleged in charging documents that Rees had known that his girlfriend had held a loaded gun to her head “mere hours before the shooting” and that she’d texted a friend, saying “I can’t keep doing this. I want to live but not like this.”

When Orem police called to check on her, the charging documents said, Rees told her if the police showed up he’d “spray them” and kill himself, and yelled at her as she sobbed.

Rose Nguyen told the judge that what happened that night wasn’t a moment of poor judgment but a pattern of cruelty from Rees. Earlier in their relationship, she said, her daughter endured emotional abuse, physical harm, and sexual violence under the threat of a firearm.

But Rees’ attorney Evan Muir rejected that there was a pattern of abuse before that day, saying, “my client never hit her, he didn’t do anything — he never committed a battery upon her.”

Addressing the judge, Rees, 31, said he hadn’t wanted her to harm herself that night and said he’s not the same person he was then.

“The regret, shame, remorse, and loss of that day is something that will never leave my mind,” Rees said.

The Nguyens detailed her prior calls and interactions with Orem police in a lawsuit they filed against the department — claims that were dismissed after the department argued in court filings that Utah’s governmental immunity law precludes them from culpability.

Rena Nguyen was studying biology at BYU, had graduated at the top of her high school class and wanted to be a radiologist, her mother said Friday at a news conference.

“That’s not just a loss for the community,” Rose Nguyen said, “but a loss for us and for those that she could help.”