Motive in the Idaho College Murders: Theories and Open Questions

No motive has ever been established in the Idaho college murders. Bryan Kohberger pleaded guilty in July 2025 to killing four University of Idaho students in Moscow, Idaho, in November 2022, but the plea deal did not require him to explain why he did it, and he declined to speak at sentencing. The prosecutor, the lead state investigator, and the sentencing judge all said publicly that the reason may never be known.¹²

What the Prosecutor Said On the Record

At the July 2, 2025, plea hearing, Latah County Prosecutor Bill Thompson walked the court through the state’s evidence and offered no theory of motive. Investigators, he said, could not establish any connection between Kohberger and the four victims: Kaylee Goncalves, Madison Mogen, Xana Kernodle, and Ethan Chapin.¹ Cell phone records placed Kohberger’s phone near the house on roughly 23 occasions between July and early November 2022, but there was no evidence he had contact with the residence or anyone living there.³

Thompson also made a point of ruling something out. There was, he told the court, “no evidence there was any sexual component or sexual assault on any of the victims.”³ The murder weapon was never recovered, which prosecutors acknowledged limited what they could conclude about Kohberger’s reasons.¹

Idaho State Police Lt. Darren Gilbertson, who worked the investigation, put it bluntly after sentencing: “He’s the only one that has the ‘why.'”¹ Thompson told reporters that FBI profilers had warned early in the investigation that the real reasons might never be known and might only hold meaning inside Kohberger’s own head.⁴

Why the Question Remains Open

The plea deal is a large part of the answer. In exchange for the state dropping the death penalty, Kohberger pleaded guilty to one count of burglary and four counts of first-degree murder, accepted four consecutive life sentences without parole, and waived all appeals.⁵ The agreement contained no requirement that he explain the crimes.² Thompson later said the deal was structured to lock in a conviction and avoid “decades of post-conviction appeals.”⁶

Because there was no trial, the fuller evidentiary record never came out in court. And when Judge Steven Hippler offered Kohberger the chance to speak at the July 23, 2025, sentencing hearing in Boise, he answered, “I respectfully decline.”⁷ The judge himself used the moment to describe the killings as an “unfathomable and senseless act of evil” and cautioned that continuing to hunt for a motive only grants Kohberger “relevance” and “power.”⁴

The Theories That Have Circulated

Madison Mogen as the Primary Target

A 2025 book by James Patterson and Vicky Ward, The Idaho Four: An American Tragedy, reported what the authors described as a “consensus” among people close to the case and the victims’ families that Mogen was Kohberger’s primary target. The book floated a scenario, attributed to friends of the victims as their “best guess,” in which Kohberger visited the restaurant where Mogen worked, expressed romantic interest, and retaliated after rejection. The book’s own sourcing presents this as conjecture, and no official evidence corroborates it.⁸ What prosecutors did establish is that the Ka-Bar knife sheath carrying Kohberger’s DNA was found on the bed next to Mogen’s body and that she was killed first.

Steve Goncalves’s Sexual-Motive Claims

Kaylee Goncalves’s father, Steve, has publicly rejected the prosecutor’s statement that the killings had no sexual component. After the gag order was lifted, he said people connected to the investigation told him Kohberger’s phone contained “weird, weird porn fetishes,” specifically involving “drunk passed out girls and gagging girls.”⁹ He also said the Latah County coroner told him there was evidence his daughter had been gagged, with “some damage around her mouth.”¹⁰ These claims directly contradict what Thompson told the court. Steve Goncalves has expressed frustration with Thompson’s handling of the case and said publicly that he does not accept the prosecutor’s characterization.

A Former FBI Profiler’s Read

Mary Ellen O’Toole, a former FBI profiler who commented publicly on the case, characterized the murders as “need-driven behavior” rooted in hatred rather than academic curiosity or experimentation. She rejected the popular idea that Kohberger’s criminology studies caused or enabled the crimes, calling it a misunderstanding of how violent offenders work.¹¹ She also pointed to the “tremendous number of elementary mistakes” Kohberger left behind, including the sheath, his phone pinging in the area, and his car circling the neighborhood, as a pattern more consistent with an emotional and reckless state of mind than a calculated one.¹² In a separate interview, she said there could be “multiple motives” at work, including both academic fascination and personal violent ideation.¹³

Background That Has Fueled Speculation

At the time of the killings, Kohberger was 28 and in his first semester as a Ph.D. student and teaching assistant in criminology at Washington State University in Pullman, about ten miles from Moscow. He had earned his bachelor’s and master’s degrees from DeSales University in Pennsylvania, where he studied under Katherine Ramsland, a nationally known expert on serial killers whose coursework included a book she co-authored with BTK killer Dennis Rader.¹¹

At Washington State, investigative documents released after the case concluded detailed nine separate complaints from students, faculty, and administration about Kohberger’s “rude and belittling behavior toward women.”¹⁴ A criminology professor told Idaho State Police she had warned colleagues Kohberger might be a “predator” and believed he was “stalking people,” and that he would physically block the doorway of an office where female graduate students worked.¹⁵ Fellow students described him as disparaging toward women and said his academic focus included “sexual burglary.”

A fellow teaching assistant told investigators Kohberger liked to talk about “criminal decision making and burglary type crimes” and frequently talked about wanting a girlfriend. The same student noticed scratches and knuckle wounds on Kohberger’s face and hands in October and November 2022, which Kohberger blamed on a car accident. About three weeks after the killings, Kohberger remarked to a fellow doctoral student that the perpetrator “must have been pretty good” and may have committed a “one and done” crime.¹⁵¹⁶

Court filings before the plea revealed that the defense had obtained neuropsychological evaluations diagnosing Kohberger with Autism Spectrum Disorder (Level 1, without intellectual impairment), Developmental Coordination Disorder, and Obsessive-Compulsive Disorder with absent insight.¹⁷ The defense was clear this evidence was not intended to argue he did not know right from wrong. The purpose was to explain his flat affect and unusual physical presentation, and to argue that behaviors like frequent hand washing and glove wearing were biological rather than consciousness of guilt. Because the case ended with a plea, these evaluations were never tested in front of a jury.

None of this background amounts to a motive. It is context about who Kohberger was, not an answer to why he picked that house on that night.

Where Answers May Still Come From

The non-dissemination order that had kept attorneys, investigators, and witnesses from discussing the case was lifted in July 2025. Judge Hippler ruled that with no trial to protect, its “primary purpose” was “no longer at play” and that the public’s right to information was “paramount.”¹⁸ Lifting the order did not compel anyone to speak, however, and the prosecutor’s office and defense team declined interview requests.¹⁹

Investigative records have started to come out. The Moscow Police Department released roughly 300 pages in July 2025, and the Idaho State Police opened a dedicated portal for their reports in August 2025, with additional agency records still under review.²⁰ The Goncalves family has said they intend to request discovery materials, including police reports, photographs, and investigative files, in hopes of finding something the plea deal did not surface.²¹ Whether any of those records illuminate Kohberger’s reasons remains to be seen. He is housed at the Idaho State Correctional Complex in Kuna, Idaho, serving four consecutive life sentences without parole.²²

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