BURLEY — The man who killed four people across two southern Idaho counties in July 2025 will spend the rest of his life in prison.

Benjamin Roy Naylor, 57, was sentenced Monday to four consecutive fixed-life terms for the murders of Kelly Jenks, 66, Donna Jenks, 62, Angelica Pearl Medina, 35, and Dennis Mix, 77. The four died July 8, 2025, in a shooting spree that shook the Cassia and Minidoka counties and involved the attention of seven area law enforcement agencies into one of the region’s most jarring homicide investigations in recent memory.

Cassia County Prosecuting Attorney McCord Larsen and Minidoka County Prosecuting Attorney Lance Stevenson announced the sentence Monday through a news release issued by the Missouri-based Vera Causa Group. Both said the outcome brought a measure of certainty to families who had endured months of proceedings complicated by mental health evaluations and competency hearings.

“This outcome allowed the defendant to take accountability for his actions, which is an important part of our pursuit of justice,” Larsen said. “Four consecutive and concurrent fixed-life sentences means Benjamin Naylor will spend the rest of his natural life in prison. That is certainty. And certainty, for these families, has value.”

Naylor was charged with the four murders July 9, 2025, and has been held in the Cassia County Jail in Burley without bond since his arrest the evening prior. A plea offer was extended in November 2025 and approved by the victims’ families before sentencing was finalized this year.

The KillingsThe investigation began July 8, 2025, when police responded to a Rupert home where Medina was found dead from a gunshot wound to the head. Doorbell camera footage showed a man matching Naylor’s description approaching and leaving her home with a firearm tucked under his jacket.

Later that evening, Cassia County deputies responded to a Burley home where the Jenks couple were found shot to death. Investigators also tied Naylor to the death of Dennis Mix, found fatally shot inside a Ford Expedition parked behind the closed Connor’s Cafe in Heyburn.

Naylor was arrested around 10 p.m. during a traffic stop on State Highway 75 near milepost 90. He was found in possession of a 1911-style handgun and was driving a gold 2013 Toyota Tundra that investigators linked to the crime scenes.

No Death PenaltyAfter consulting with all four victims’ families, prosecutors chose not to pursue the death penalty as part of the plea agreement.

Larsen said the decision came down to the realities of prosecuting a defendant with a severe, documented mental illness.

“Seeking the death penalty means years of litigation, appeals, habeas petitions and retraumatization at every stage,” Larsen said. “The alternative — a plea to fixed-life sentences with certainty — means no trial, no cross-examination of the families, no risk of acquittal or reversal, and a defined endpoint to the legal chapter of their lives. It does not end the grief. Nothing does. But it ends the legal prolonging of it. In this case, the families made an informed, courageous decision. They chose certainty. I have enormous respect afor that.”

Mental Illness and Idaho LawThe case put into focus the legal landscape around mental health in the Gem State, which became one of the first states in the nation to abolish the insanity defense in 1982. Under Idaho code, a person’s mental condition is not a defense to any charge of criminal conduct — a law upheld by both the Idaho Supreme Court and the U.S. Supreme Court.

Mental illness, however, is not without legal relevance in Idaho. It can be used to challenge whether a defendant possessed the specific intent a crime requires. It can pause proceedings when a defendant is found incompetent to stand trial —a crucial aspect in Naylor’s case — and courts must consider it at sentencing.

Naylor underwent court-ordered competency evaluations after his arrest, which stalled his preliminary hearing for months. Stevenson acknowledged the frustration that process caused but called it a constitutional necessity.

“It’s not a loophole; it’s a constitutional guarantee,” Stevenson said. “Victims’ families are languishing and waiting for justice. Our evidence is sitting. Witnesses’ memories fade. We have an obligation to secure a conviction which will withstand scrutiny for decades. That means letting the process run its course, even when the pressure to move quickly is intense.”

Child Support ProvisionThe Minidoka County plea agreement carried an unusual provision in that Naylor must pay child support to Medina’s children — a condition her family specifically requested. Medina left behind four children — Neriah, Emily, Damian and Olivia.

“This part of the agreement does not replace a father or a mother,” Stevenson said. “It is a formal recognition that those children’s futures were altered by this crime and that the person responsible has an obligation that extends beyond prison walls.”

A Call to the CommunityBoth prosecutors used Monday’s announcement to call on the Mini-Cassia community to confront the role mental illness played in the tragedy — and to push for better resources before the next crisis arrives.

“The legal resolution of this case does not mean the community’s healing is complete,” the joint statement reads. “Four people are gone. Families are forever changed. We as a community have to reckon with how we address mental illness before it reaches the point of tragedy. We have to fund mental health services. We have to reduce the stigma that keeps people from seeking help.”

Larsen also addressed the toll the case took on Naylor’s own family, who issued a public apology in July 2025 and acknowledged he had struggled with severe mental illness for most of his life.

“They are grieving too,” Larsen said. “They are grieving the person they knew before the illness progressed. That grief is real, and it is largely invisible to the community.”