Caleb Rees received four consecutive prison terms after admitting reckless actions contributed to the death of 20-year-old BYU student Rena Nguyen.

PROVO, Utah — A Utah man has been sentenced to four consecutive prison terms after pleading guilty to reckless manslaughter and other felonies in a case centered on his treatment of his girlfriend while she was in a severe emotional crisis before she died by suicide. Fourth District Judge Sean Petersen sentenced Caleb Aidan Rees, 31, on July 17 to four terms of zero to five years, giving him credit for nearly two years already spent in jail.

The sentence marked the latest and most consequential turn in a case that began with the Oct. 1, 2021, shooting of 20-year-old Rena Nguyen, a Brigham Young University biology student. Prosecutors eventually argued that Rees did not merely happen to leave a firearm accessible. They said he knew Nguyen was suicidal, berated and demeaned her during hours of conflict and left her alone with a loaded handgun after moving it to a place where she could see it. Rees pleaded guilty in April 2026, nearly five years after the shooting and almost two years after prosecutors filed charges.

Petersen said an audio recording from Nguyen’s phone made the case particularly troubling. At sentencing, he described what he heard as “nothing short of horrific” and said Rees’ repeated threats, ridicule and demeaning comments raised concerns about his future relationships and public safety. The judge told Rees that a young woman with significant promise had died in part because of his reckless actions and indifference. Petersen imposed consecutive terms for reckless manslaughter, two counts of possession of a firearm by a restricted person and possession of drugs with intent to distribute, all third-degree felonies under the plea agreement.

The recording became central to the prosecution because it documented the hours before the shooting in a way investigators did not initially have from witnesses. At a 2025 preliminary hearing, Orem police officer Jeffery Randall testified that one recording began at about 3:20 a.m. and continued for roughly 14 hours, remaining active even after the shooting. Court reporting described Nguyen crying as Rees accused her of dishonesty and infidelity, called her degrading names and argued with her about police involvement. Prosecutors said Rees was aware she had recently expressed suicidal thoughts to a friend, making her condition known rather than merely foreseeable in hindsight.

The immediate crisis began after a friend contacted police out of concern for Nguyen. Earlier that day, prosecutors said, Nguyen had sent a message saying she had held a loaded gun to her head and wanted to live but could not continue as things were. Police conducted part of their welfare check by phone. Defense attorneys later argued that because officers did not believe an in-person intervention was required at that point, Rees could likewise have believed the immediate danger had passed. Prosecutors rejected that reasoning, pointing to what they said Rees personally saw and heard from Nguyen during the hours that followed.

The parties also sharply disputed the meaning of Rees moving a handgun inside the home. The defense told the court that he moved the gun several feet farther from where Nguyen was, describing that action as an attempt to reduce her access to it. Prosecutors said the movement instead placed the loaded weapon in her direct line of sight and that Rees then left the room despite knowing she was suicidal. Charging documents said Nguyen got up shortly after he left, went to the table and used the handgun. Emergency responders took her to a hospital after the shooting, and earlier court reporting said she died there two days later.

Nguyen’s parents, Rose and Keith Nguyen, told the sentencing court that their daughter should have been preparing for the future rather than becoming the subject of years of court proceedings. Rose Nguyen described the case as involving sustained cruelty rather than a single error in judgment. Keith Nguyen remembered his daughter as bright, kind and full of promise. The family has said she came to Utah from Northern California to study biology at BYU and hoped eventually to become a radiologist. Her mother has said she graduated at the top of her high school class and wanted a career in which she could help others.

The criminal case emerged long after the first police investigation. Rees was not charged with manslaughter until August 2024. The delay followed years in which Nguyen’s family questioned how Orem police handled her earlier reports and the circumstances surrounding her death. In 2023, her parents filed a civil lawsuit alleging officers failed to protect their daughter despite prior contacts in which she described violence and threats. That complaint alleged Nguyen had called police in December 2020 after Rees was handling firearms while intoxicated and had later told police in June 2021 that he had physically abused her and previously held a gun to her face.

The civil complaint made allegations that were broader than the conduct ultimately resolved by Rees’ criminal guilty pleas. Nguyen’s family alleged physical, emotional and sexual abuse during the relationship and accused Orem police of failing to take required protective action. Rees’ attorneys disputed that broader description of a continuing pattern. At the 2026 sentencing, a defense attorney rejected claims that Rees had repeatedly battered Nguyen before the day of the shooting. The lawsuit against the police department was dismissed after the city argued that Utah governmental immunity law barred the claims, according to subsequent reporting on the case.

The family’s continued effort to examine the case helped bring renewed attention to recordings that became important to prosecutors. Reporting on the investigation said a private investigator retained by the Nguyen family reviewed material from her phone and helped bring the audio evidence to the forefront. Prosecutors later used the recordings, together with testimony about the firearm and Nguyen’s earlier communications, to argue that Rees had consciously disregarded a substantial risk. Petersen eventually ordered Rees to stand trial in May 2025, finding enough evidence for the manslaughter and related cases to proceed beyond the preliminary stage.

Rees ultimately avoided trial by entering a plea agreement in April. Reporting from the sentencing said the agreement reduced the manslaughter count and one controlled-substance count from second-degree to third-degree felonies and resolved the case with four felony convictions. Several other gun and drug charges were dismissed. The agreement also permitted a recommendation that the four sentences run consecutively. Adult Probation and Parole had recommended a substantially shorter period in jail before probation, according to defense counsel, but Petersen rejected a probationary disposition and ordered prison terms that together expose Rees to as much as 20 years.

Before the sentence was imposed, Rees told the court he was ashamed of the way he had spoken to Nguyen and said he had not wanted her to hurt herself. He said the events would remain with him and argued through counsel that he had changed during the years since Nguyen’s death. His lawyer said Rees called 911 after the shooting and attempted to help while waiting for emergency responders. Prosecutors said remorse did not erase the risk he knowingly created and emphasized the gap between describing the firearm as simply left behind and the larger context captured in Nguyen’s recording.

The sentencing closes the central criminal case without resolving every disagreement surrounding Nguyen’s relationship, the earlier police response or the long path to prosecution. What is no longer disputed in the criminal proceeding is that Rees accepted responsibility for reckless manslaughter and three other felony offenses. He will serve the indeterminate sentences under Utah’s prison system, with the consecutive terms allowing a maximum total of 20 years. The case that began with a 2021 welfare concern and shooting has therefore ended, for now, with a felony judgment and a prison sentence imposed in Provo nearly five years later.

Author note: Last updated August 23, 2026.