What made their deaths all the more terrifying was how elusive their killer seemed — until a sudden arrest made everything even scarier. Sometime after midnight on November 13, four University of Idaho students — Xana Kernodle, Ethan Chapin, Madison Mogen, and Kaylee Goncalves — were all viciously attacked while sleeping in an off-campus townhouse. They were each, as eventual criminal charges would , “stabbed and murdered with premeditation with malice and forethought.” Throughout the seven tense weeks that followed, the case now known as the Idaho student murders rocked the small town of Moscow, Idaho, became a riveting true crime obsession, and sparked a global media frenzy. But although everything that happened after their deaths would become international news, the lead-up to the quadruple homicide was completely uneventful. And so, nothing seemed to stick: There were no suspicious actions, changes, or alarming behaviors prior to the murders, and no immediate suspects, no big compelling clues, no key witnesses in the aftermath. An unknown intruder or intruders had simply entered the house, stabbed to death four of the six sleeping students inside, and then quietly slipped into the night. Still, as the University of Idaho community struggled to come to terms with the killings and cope with their fear of the perpetrator, local and federal investigators were hard at work. By late December, despite the massive amount of resources devoted to the investigation, along with a stream of steady , the case appeared to be on the verge of going cold. But on December 30, Moscow police announced they’d made an in the case. Bryan Kohberger, 28, had no apparent connection to any of the victims. Instead, he was a graduate student at a neighboring university, with an unsettling history and an obsession with true crime. The abrupt identification of the alleged killer, and the excavation of his personal background, meant that one of the most senseless, shocking crimes in recent memory became even more tragic. Had four devoted friends — two of whom were dating, two of whom were lifelong best friends — lost their lives to a would-be serial killer? The probable cause , released Thursday after Kohberger’s first court appearance, sheds new light on an extraordinarily horrific crime and the equally extraordinary criminal investigation that followed it. What finally led to Kohberger’s arrest was simply excellent investigative work: a mix of well-organized policing, groundbreaking forensics using genetic genealogy, and old-fashioned detective work.

The murders

Xana Kernodle, Ethan Chapin, Madison Mogen, and Kaylee Goncalves , all involved in the campus Greek system, and all fast friends. Kernodle, 20, was a bubbly junior majoring in marketing; she was dating Chapin, 20, a triplet and a fun-loving sports management major. Mogen and Goncalves, both 21, had been inseparable since the sixth grade. They did everything together: lived together, went to school together, and, ultimately, . On the night of Saturday, November 12, 2022, everything seemed normal. Kernodle and Chapin went to a party at the Sigma Chi fraternity; Mogen and Goncalves went out to a bar, then hung out at a food truck for a bit. By 2 am Sunday, according to the probable cause affidavit, everyone had gathered at the house on King Road where Mogen, Goncalves, and Kernodle lived with two other roommates. Goncalves, as in January by Dateline, had recently moved out of the townhouse as she prepared to graduate early and take a job in Austin, Texas, but she’d returned for the weekend to hang out with Mogen. Months later, this news would fuel public speculation that whoever was watching the house saw her return — and saw it as an opportunity. The three-story was accessible primarily by a secure door with a coded entry on the bottom floor, as well as by a sliding glass door on the main level (second floor) of the house. The lower entry was locked, but the sliding glass door might have been more easily accessible.

Angela Palermo/Idaho Statesman/Tribune News Service via Getty Images

At 4 am, Kernodle ordered Jack-in-the-Box; at 4:12 am, she was on her phone, surfing TikTok. Sometime in the next few minutes, the attack began. She off her attacker — but by 4:25 am, she and her boyfriend would both be dead.

Note: the following section contains disturbing details of the crime.

The killer attacked on the second and third floors of the house, entering each of the victims’ rooms for separate attacks — but he left the roommates on the main and lowest floors alive. He used a large Ka-Bar of the style used by the US Marine Corps. Nearby surveillance footage captured audio of the attacks around 4:17 am, including distressed sounds and barking from Goncalves’s dog. As revealed in the affidavit, one roommate told police she heard noises and crying, but didn’t understand what she was hearing. Although she opened her door repeatedly to see what was happening, she saw nothing alarming — though she did report hearing Goncalves say, “There’s someone here.” Some time later, over sounds of crying coming from Kernodle’s room, she heard a male voice saying, “It’s okay, I’m going to help you.” The third time she opened her door, it was to the sight of a man clad all in black and wearing a mask, walking toward her. As she stood in “frozen shock,” the killer walked by her room; it’s unclear whether or not he saw her. With his face mostly covered, the roommate noted the only thing she could see clearly: the suspect’s “bushy eyebrows.” That detail would later prove accurate. Still stunned, the roommate returned to her room and locked her door, while the killer exited through the sliding glass door on the apartment’s main floor. Then he vanished.

The aftermath: A media frenzy and public speculation run amok

On Sunday, at 11:58 am, 911 received a phone call from a roommate’s phone, during which multiple people at the scene spoke to the dispatcher. This 911 call has not been released, but there’s been considerable confusion due to reports of “” at the scene. Police that “the surviving roommates summoned friends to the residence because they believed one of the second-floor victims had passed out and was not waking up”; this statement, however, led to widespread from the public about how a bloody crime scene involving multiple fatalities could have been so misunderstood and misreported. The murders immediately made national headlines and left the community in disbelief. Despite police initially there was no “ongoing community risk,” the panic was real. Once news of the deaths broke, so many students on the 11,000-member University of Idaho campus that the university decided to allow students an optional early Thanksgiving break. Concerned calls to 911 , and residents of a Ted Bundy-like predator stalking and choosing their victims randomly. Early police statements didn’t help clear this up; after initially releasing contradictory statements about whether the attack had been personal or random, police settled on the that it was “an isolated, targeted attack,” but that they had “not concluded if the target was the residence or its occupants.”

Ted S. Warren/AP

Online sleuths immediately latched onto the murders, with speculation running rampant both locally and online. Police released taken the night of the murders, from unrelated nearby interactions. It’s unclear if the footage led to tips that proved useful in Kohberger’s eventual arrest, but it did lead to a flurry of rumors and speculation that brief, blurry motion in the background of the video might be a group of people running from the crime scene. On the hunt for clues, people pored over the four victims’ social media, accusing everyone from their friends to who showed up in the background of Instagram photos. The food truck, which ran a Twitch livestream, became a of public speculation, with people examining footage of Goncalves and Mogen hanging out by the truck, looking for any clues that someone may have been stalking the two women. Police had to issue statements formally clearing multiple people (and ) of suspicion, the surviving roommates, an ex-boyfriend of one of the victims who she had repeatedly called the night of the attack, a random man who was at the food truck, and, , a University of Idaho professor who was fingered for the crime by the “” of a tarot reader on TikTok. (The tarot reader the professor ordered Kohberger to carry out the murders.) That bonkers sidebar in this morbid case lends an idea of how chaotic things looked from the sidelines: a heinous crime, with an apparent lack of witnesses, no significant leads, and a lack of serious suspects — but plenty of distracting, obfuscating, unhelpful social media noise. When, on December 7, police locating a white Hyundai Elantra that had allegedly been spotted at the crime scene, it seemed to many people to be less like a real, promising lead and more like busywork: After all, a generic white car? What could be more of a needle in a haystack? But as improbable as it seemed, police focus on that generic white car was exactly right. Five days after the murders, a at Washington State University on his white 2015 Hyundai Elantra, before driving it cross-country from Idaho to his parents’ home in Pennsylvania. His attempts to prevent authorities from tracing the car, however, overlooked one thing: Police had his DNA.

The investigation and arrest of Bryan Kohberger

What’s striking about the investigation into Kohberger, as the affidavit makes clear, is both how quickly police homed in on him as a person of interest, and how seamlessly multiple law enforcement agencies worked together to apprehend him — collaborating across multiple states, jurisdictions, and even the country. The first big lead in the case came from nearby surveillance footage, which captured a “white sedan” repeatedly circling the neighborhood between 3:20 am and 4:20 am.

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Police tracked the car to Pullman, Washington, about 10 miles away, home to the Washington State University campus. Meanwhile, an FBI expert identified the make and model, and even narrowed down the year range of the car: a 2014-2016 Hyundai Elantra. With that detail in hand, WSU campus police officers quickly tracked down a Hyundai Elantra owner who attended the school and lived near the last place the car had been seen on surveillance the night of November 13: Kohberger. By November 29, just over two weeks after the murders, the Moscow Police Department had a copy of Kohberger’s driver’s license photo, complete with his “bushy eyebrows.” Cell phone records showed Kohberger’s phone traveling from Pullman in the direction of Moscow the night of the murders, before it was shut off completely between 2:47 am and 4:48 am — “consistent with Kohberger attempting to conceal his location during the quadruple homicide,” according to the affidavit. They also showed Kohberger apparently returning to the scene of the crime in Moscow at approximately 9 am that day — still several hours before authorities would be alerted to the scene — and then immediately returning to his house in Pullman. But while authorities had strong circumstantial evidence tying Kohberger and his white car to the crime, the smoking gun in this case had been recovered from the crime scene on the first day of the investigation: an empty knife sheath with a trace of DNA from an unknown male.

Armed with this clue, authorities the groundbreaking technique that’s led to arrests in many cases since the 2018 arrest of the Golden State Killer: genetic DNA matching. In this process, investigators upload DNA to genealogy websites and then build out a potential family tree for a suspect (or, in many cases, an unidentified missing person). Then, using context clues and other practical detective work, they follow the family tree and trace which member is most likely to be a match.

The use of genetic genealogy is controversial. Currently, only two genealogy websites, GEDmatch and Family Tree DNA, allow law enforcement to use DNA from their users. Both are opt-in, meaning the user has to give explicit consent for the use, though GEDmatch to opt in and boasts that its genetic DNA matching has assisted in closing over 500 cold cases. That number seems accurate given how regularly genetic DNA matching is now used to solve crimes — and it may soon be even higher thanks to a that could allow police to more quickly zoom in on the correct branch of a DNA family tree. Police were able to match the DNA on the knife sheath with DNA from Kohberger’s father, gathered from trash at Kohberger’s parents’ home. And that match was definitive, excluding 99.99 percent of the population from being the father of the suspect. Meanwhile, Kohberger and his dad embarked on a multi-day road trip from Washington to Pennsylvania. License plate readers across the country mapped them traveling from state to state: Colorado, Indiana, Pennsylvania. On December 15, they were by Indiana patrol officers in a very short timespan for tailgating. A law enforcement source later that a task force which had Kohberger under surveillance requested that the Indiana troopers pull him over specifically so that they could get a glimpse of his hands to see if there were any cuts or other injuries. (In of one of the two stops, Kohberger and his father appear only briefly on camera.) The FBI, allegedly part of the task force, later denied to Fox that it had given any orders to waylay Kohberger; it’s unclear if the task force was acting independently, or if the two stops were a complete coincidence. On December 30, after surveilling Kohberger for several days, the Pennsylvania State Police executed on the home of his parents in the largely rural Chestnuthill Township, complete with smashed windows and broken doors. After being extradited back to Idaho, all the while under constant media , Kohberger appeared in the Latah County District Court in Moscow on Thursday, January 5, and documents related to his arrest were unsealed by the court.

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That was the first time the world had heard of Bryan Kohberger. But internet sleuths quickly got to work uncovering his strange and ominous background.

The fallout: Kohberger, his background — and what’s next

Kohberger was a Pennsylvania native who grew up in the suburbs. His high school classmates described him as “analytical,” interested in human behaviors — but one friend a physically and emotionally abusive friendship to the New York Times that “got so, so bad that I just shut down when I was around him.” Kohberger graduated from Northampton Community College in 2018 with an associate degree in psychology; two years later, he graduated from DeSales University, then went on to study criminology there as a grad student. While there, he took classes under legendary forensic profiler Katherine Ramsland, a in the world of true crime thanks to her long career and dozens of books covering famous cases. He also participated in a research study into criminal behavior, for which he on Reddit using a retroactively chilling : “This study seeks to understand the story behind your most recent criminal offense, with an emphasis on your thoughts and feelings throughout your experience.” After getting his master’s degree in 2022, he began studying at Washington State as a criminology and criminal justice doctoral student.

There are striking parallels between Kohberger and the Golden State Killer, Joseph DeAngelo Jr. Both men gravitated to law enforcement: DeAngelo was a police officer; Kohberger worked as a security guard for a local school district and had recently with his local police department, claiming he wanted to aid rural law enforcement with data collection and analysis. Both had glowing newspaper write-ups for small acts of valor they had performed.

Both men also cased their crime scenes extensively: phone records showed Kohberger returning to the area of the King Road house again and again — “on at least 12 occasions” per the affidavit — beginning in June 2022, the earliest date that police could obtain records. That might be significant for multiple reasons. One of the rumors police downplayed about the case was that Kaylee Goncalves had expressed fear of a “” in the weeks prior to the murders. This led to heated speculation that Goncalves was the focus of the attack, but authorities have never confirmed this. The evidence, instead, might point toward Kohberger being fixated, as authorities originally suggested, on the house itself. Kaylee’s father, Steve Goncalves, who’d of police during the many weeks of scant updates, had nothing but praise for the investigation after the arrest, in a January 5 interview that “all is forgiven.” “People think Idaho is so old-fashioned and outback, but these guys — they hit a home run, man,” he said. “That affidavit is impressive.” “Impressive” might be an understatement: The swiftness with which police managed to identify, carefully build a strong case against Kohberger, track him across the country, and arrest him, all while working with multiple agencies and somehow managing to keep his identity from leaking to the public, is extremely rare. It’s even more extraordinary given how many victims were involved, how unusual the crime was, how many agencies were involved, and how intense the public and media scrutiny was. The triumph of the investigation, however, is tempered by the realization that Kohberger seems to have been working the criminal justice system in order to become a better criminal. Each half of the resolution to this case is a cold counter to the other: On the one hand, a picture of what we all, desperately, want policing to look like; on the other, a picture of what the criminal justice system too often becomes: exploitable. Still, it’s easy to imagine this investigation becoming a major case study for what effective policing can and should look like: law enforcement working with the community and with each other, and building the case methodically, based solely on the evidence. Perhaps most unusual of all is just how strong the case against Kohberger appears from the outset. Eyewitness? Check. Video surveillance of his car? Check. DNA match? Check. Implicating cell phone records? Loads. Even without the added circumstantial evidence of Kohberger’s own obsession with criminal psychology, this would be a hard defense to mount. And we know all of this just from the probable cause affidavit — which typically only contains enough information to make the case for an arrest. The trial process itself will likely reveal much more information about the crime and the alleged criminal. Although the probable cause affidavit was unsealed and made public, Latah County Magistrate Judge Megan Marshall had previously issued a non-dissemination order — — in the case, forbidding authorities to communicate with the media. It’s not clear how that order will affect the future release of public documents in the case. Kohberger’s preliminary hearing is scheduled for January 12. He is without bail on four felony charges of first-degree murder and one charge of burglary with intent to commit a felony. While the focus remains on the four deceased victims, the surviving roommates have also had to deal with their own trauma, as well as endure public suspicion and scrutiny. At the January 5 hearing, the judge granted a request for a no-contact order for a period of two years between the families of the four victims and their roommates — another sad grace note in a case full of heartbreaking details. Still, the bond these friends all shared can’t be broken. They leave us a legacy of living life to the fullest, of unabashed joy and camaraderie that shines throughout the wide digital footprint of the students’ social media. In a , made on the day of the murders, Goncalves snapped several photos of her roommates, including Kernodle, Mogen, and Chapin. “One lucky girl to be surrounded by these ppl everyday,” she wrote.

Update, January 18, 10:10 am: This story was originally published on January 7 and has been updated to include the revelation that Kaylee Goncalves had moved out of the townhouse, and that the FBI denies having given orders to delay Kohberger via traffic stop.