Why Did Bryan Kohberger Murder 4 University of Idaho Students? Investigator Shares Chilling Possible Theory | Oxygen
When Bryan Kohberger pled guilty to killing four University of Idaho college students, he left one lingering question: Why?
In July 2025, Kohberger admitted to fatally stabbing Kaylee Goncalves, Madison Mogen, Xana Kernodle and Ethan Chapin—only providing short yes or no answers while admitting his guilt, according to previous reporting from Oxygen.com.
But the former criminology doctoral student—who has recently made new claims of innocence from behind bars—never provided a motive for the 2022 slayings.
Now, an FBI investigator tied to the case is providing a possible theory in Netflix’s The Idaho Murders: College Nightmare, speculating that Kohberger may have taken his academic fascination with crime into the real world.
“I guess the question would be: Do you want to go out and experience that yourself?” former FBI Special Agent Ed Jacobson asked. “Are you continuing your research because you've got this fascination and draw to commit these crimes? But, that is just a theory.”
Bryan Kohberger’s Classmate Describes Crime Fascination
Before carrying out the murders, Kohberger—who grew up in Pennsylvania in a working class family—earned a masters in criminology from DeSales University, where he studied alongside famed professor of forensic psychology Katherine Ramsland.
“We studied in Dr. Ramsland’s class every big killer, every little killer, killers that people have never heard of,” Kohberger’s classmate Lilly Karaban recalled in the docuseries of their Minds of a Serial Killer class. “We did have group projects with mock crime scenes to figure out how a crime scene took place, what kind of killer would do a crime scene like this.”
Karaban remembered the usually quiet Kohberger being actively engaged in the course work, often asking questions and taking copious notes.
“Brian adored Professor Ramsland,” she said, “It was like a switch went off in his head in that class.”
He even conducted his own research project in a survey on Redditt asking those who’d committed crimes to provide information “to understand how emotions and psychological traits influence decision making when committing a crime,” according to an affidavit previously obtained by Oxygen.com.
As Gonclaves sister Alivea Goncalves explained in the docuseries, “it almost seemed like preparation for the perfect crime.”
Ramsland herself even speculated on whether the coursework could have influenced the murders in a 2025 interview with NewsNation, saying, ““I have to look at the framework of what I taught and wonder, did I inspire him in some way?”
RELATED: New Photos Show Xana Kernodle's Final Meal Before Brutal University of Idaho Murders
Kohberger has never directly addressed any potential theories on his motive. His attorneys considered using an "alternate perpetrator" defense, but a judge ruled they would not be able to name any possible perpetrators at trial or present an alibi defense, according to CNN. His defense attorneys had argued prior to his plea that he had been out stargazing in the early morning hours of Nov. 13.
After earning his master’s degree, Kohberger moved across the country. At the time of the murders, he was pursuing a doctorate degree in criminology and working as a teaching assistant at Washington State University.
Through interviews with staff, faculty and students at the university, investigators learned that Kohberger was not well liked and was the subject of numerous complaints, according to court documents released by the Idaho State Police.
“There had been incidents with Bryan with faculty,” Jacobson said. “There had been incidents with Bryan with female students. Very demeaning behavior, mansplaining.”
Moscow Police Chief Anthony Dahlinger added that he “had made a lot of them feel uncomfortable” and had a reputation for talking down to women. He was ultimately fired from his teaching assistant position on Dec. 19, authorities said.
Teachers also expressed concerns about Kohberger’s interaction with women, per the court records.
As one teacher remarked in a meeting about Kohberger’s behavior, according to the records, “Mark my word, I work with predators, if we give him a PhD, that’s the guy that in many years when he is a professor, we will hear (he) is harassing, stalking, and sexually abusing... his students.”
After the stories surfaced, investigators considered whether Kohberger could have been part of the incel movement, a term used to described an involuntary celibate group who believes women will only date a small minority of men.
“They believe that women are the cause of all of their suffering, pain, their lives,” Jacobson told Netflix. “So they lash out and they become violent. But when it comes to using this in court, we never saw evidence that shows Bryan Kohberger is part of the incel movement.”
In the early morning hours of Nov. 13, 2022, Kohberger snuck into an off-campus home in Moscow, Idaho and killed four University of Idaho students.
Though Kohberger has never explained his actions that morning, investigators suspect that he likely attacked Mogen—who was sleeping in the same bed as Goncalves— first in a third floor bedroom.
“It appears that Kaylee might have woken up during the time that Maddie was being stabbed, and then she gets stabbed multiple times,” Jacobson said in The Idaho Murders: College Nightmare. “We believe that after, the comforter was put back over them.”
Authorities believe Kernodle likely heard the commotion and either went upstairs to check on her roommates or ran into Kohberger on the stairs and he chased her into her room, according to court records.
“Ethan is lying in the bed at the time. Bryan stabs Ethan and then back to a fight with Xana,” Jacobson explained. “She had defensive wounds all over, she had over 50 stab wounds on her. She put up a fight.”
After killing the four, Kohberger briefly made eye contact with surviving roommate Dylan Mortensen, who opened her bedroom door to check on the roommates, but left without ever attacking her, per the court documents.
Bryan Kohberger Denies Carrying Out the Killings From Prison
For years, Kohberger has stayed quiet about the killings, until July 26 when he provided a statement to The New York Times professing his innocence from prison.
“My actual innocence is my truth,” he said in the written statement, “and the plea, hinged on by false promises and blatant disinformation, MUST be withdrawn.”
Kohberger declined to comment on the evidence used against him or provide any details about his new claims.
He pled guilty to the murders in July 2025, receiving four life sentences in exchange for prosecutors dropping the death penalty. When asked in court whether he carried out the crimes, he replied “yes,” according to previous reporting from Oxygen.com.
Kohberger was not required to explain why he committed the murders.
“He should have to tell them why he did it,” Kernodle’s dad Jeff Kernodle contended in the docuseries. “Tell all of us parents why he did it if he was gonna get the plea.”
Though investigators believe they’ve caught the right man, the exact reason Kohberger targeted the college students remains a mystery.
“Ultimately, we never have been able to answer that question that everybody wants answered is why?,” Dahlinger said in the docuseries. “We don’t know why. We don’t know why these four. We don’t know why this house. I don’t think we’ll ever know.”