Utah Man Pleads Guilty to Killing Ex-Girlfriend Whose Body Was Found in Box in His Trunk

BLUFFDALE, UTAH — A Utah man has pleaded guilty to aggravated murder after police discovered his former girlfriend’s body inside a cardboard box in the trunk of his vehicle during an investigation into suspected impaired driving.

Jacob Holt Johnson, 42, of Herriman, pleaded guilty on October 22, 2026, in the killing of 30-year-old Summer Tatiana Roney. Under a plea agreement, prosecutors agreed not to seek the death penalty, and Johnson agreed to serve life in prison without the possibility of parole. His sentencing is scheduled for December 17.

The case first came to light on New Year’s Eve in 2024, when officers found Johnson unconscious inside his Jeep at a 7-Eleven in Bluffdale, south of Salt Lake City.

Police Make Disturbing Discovery During DUI Investigation

On December 31, 2024, officers responded to the parked Jeep, which was reportedly occupying multiple parking spaces. While investigating the situation, police discovered Roney’s body inside a cardboard box in the vehicle’s trunk.

According to authorities, Roney had an extension cord around her neck and visible bruises and cuts on her head, arms and legs. She was pronounced dead, and investigators began examining the circumstances surrounding her death.

Officers also found several items inside the vehicle, including a hammer with blood on it, a hatchet, a knife, a gas can and a bottle of bleach.

The discovery transformed what began as an investigation involving a potentially impaired driver into a homicide investigation.

Johnson was taken into custody as investigators worked to determine what had happened to Roney and how her body had ended up in his vehicle.

Investigators Search Johnson’s Home

Detectives obtained a search warrant for Johnson’s home in Herriman, where investigators reported finding blood throughout the residence and apparent signs that someone had attempted to clean up a crime scene.

Authorities also found a bat on the kitchen floor that appeared to have been recently washed, according to information released by the Salt Lake County District Attorney’s Office.

The evidence collected at the residence became part of the investigation into Roney’s death.

During questioning, Johnson told police that he and Roney had argued about the end of their relationship. Investigators said the former couple had been involved in an on-again, off-again relationship.

Authorities also reported that Johnson had been abusive toward Roney.

The investigation focused on the events leading up to her death, the evidence recovered from Johnson’s home and vehicle, and the circumstances surrounding his actions afterward.

Family Last Saw Roney on Christmas Day

Roney’s family was left searching for answers after she failed to appear for work shortly before her body was discovered.

Her sister, Michelle Tischner, told local media that she had last seen Roney on Christmas Day, December 25, 2024.

Roney was reportedly scheduled to work an afternoon shift on December 30 but did not arrive. Her body was found the following day.

The missed shift and the family’s concerns became part of the timeline investigators examined as they reconstructed the final days of Roney’s life.

Her death devastated relatives and friends who remembered her as a caring person with a vibrant personality.

In a statement released through the family’s attorney, relatives described Roney as “a vibrant, kind, and loving soul who touched the lives of everyone she met.”

They said she was deeply loved by her family, friends and coworkers, who would remember the happiness she brought into their lives.

The family also described the loss as leaving an irreplaceable void in their hearts.

Johnson Admits Responsibility in Court

Nearly two years after Roney’s death, Johnson entered a guilty plea to aggravated murder.

During the court proceeding, he acknowledged his responsibility, saying, “I caused the death of Summer,” according to reporting by KSL.

The plea agreement resolves the murder charge without a trial. In exchange for Johnson’s guilty plea, prosecutors agreed not to pursue the death penalty.

Johnson agreed to a sentence of life imprisonment without the possibility of parole, meaning he will not be eligible for release through the ordinary parole process if the court imposes the agreed sentence.

His formal sentencing hearing is scheduled for December 17, 2026.

The plea marks a significant development for Roney’s family, who have spent nearly two years coping with her death and waiting for the criminal case to reach a resolution.

A Case That Began With a Routine Police Response

The circumstances of the discovery drew widespread attention because officers initially encountered Johnson while responding to a situation involving a vehicle parked at a gas station.

The subsequent discovery of Roney’s body, the items found inside the Jeep and the evidence recovered from Johnson’s home prompted a much broader investigation.

Authorities later connected the case to the former couple’s troubled relationship and the events surrounding their separation.

Although the guilty plea establishes Johnson’s criminal responsibility for Roney’s aggravated murder, the loss to her family remains profound.

For those who knew Roney, the focus is now on remembering her life rather than the circumstances of her death. Her family’s statement emphasized her kindness, the relationships she valued and the lasting impact she had on the people around her.

With sentencing scheduled for December, the case is approaching its final formal stage in court.

Sources: PEOPLE — Original Report