When the Night Comes Falling, a 2024 nonfiction book by investigative reporter and Edgar Award–winning author Howard Blum, offers an account of the mysterious murders of four University of Idaho students on November 13, 2022. Blending novelistic prose with rigorous investigative research, Blum’s true-crime book lifts the veil of secrecy imposed by a judicial gag-order to provide a unique, behind-the-scenes glimpse into the multifaceted police investigation that led to the arrest of graduate student Bryan Kohberger. Blum, who conducted 324 interviews for the book, weaves a detailed account of the lives of the four victims, as well as of the troubled history of the suspect charged in their murders.

This guide refers to the 2024 Harper Collins hardcover edition of When the Night Comes Falling.

Content Warning: The source text and this guide discuss murder.

Summary

On December 15, 2022, a father and son set off on a 2,500-mile drive from Pullman, Washington, to the father’s home in Albrightsville, Pennsylvania. Behind the wheel of the Hyundai Elantra is 28-year-old Bryan Kohberger, a graduate student in criminology just completing his first semester at Washington State University. In the seat beside him, his father, Michael Kohberger, tries to calm his growing fears about Bryan, who had a troubled adolescence and whose moodiness and slippery personality have made him almost a stranger to his family. Foremost in Michael’s mind is a recent, horrific event that has traumatized the town of Moscow, Idaho, just 10 miles from his son’s campus home: In the early hours of November 13, four University of Idaho students were slashed to death in their bedrooms by an unknown assailant. The police have announced no suspects or motive, but Michael cannot shake a nagging feeling that his son, who has been behaving oddly, has some connection to the massacre—or else to some other terrible crime. Worsening his anxiety, their car is pulled over twice within a span of minutes, first by a sheriff’s deputy and then by a state trooper, both times for tailgating. Each time, Bryan is let off with a warning. Unbeknownst to him or his father, an FBI airplane glides above them, closely tracking their movements.

The victims of the unexplained massacre in Moscow, Idaho, are Madison Mogen, Kaylee Goncalves, Ethan Chapin, and Xana Kernodle. All between the ages of 20 and 21, the four students were murdered in a single location, an off-campus, six-bedroom house on King Road, just off highway 95. Two of the victims (Kaylee and Ethan) were not permanent residents of the house but were just visiting for the weekend: Ethan was in a relationship with Xana and was spending the night with her, and Kaylee, set to graduate in December, had come down from her hometown of Coeur d’Alene on a “whim” to visit her best friend Madison, whom she had known since the sixth grade. Two other students staying in the house, Dylan Mortensen and Bethany Funke, were not attacked. The killer had entered the house around 4:00 am by an unlocked door on the second level and had climbed straight to the third floor, where he fatally assaulted Madison and Kaylee in their sleep with a military-style KA-BAR knife. During his struggle with Kaylee, the killer dropped the leather sheath for his knife. Returning to the second floor, he was met in the hallway by Ethan, whom he killed instantly with a single slash to the throat. He then murdered Xana in her bedroom and slipped quickly out of the house by the kitchen door. Mysteriously, neither of the surviving housemates called 911 until seven hours had passed—even though one of them (Dylan Mortensen) saw the masked killer walk right past her on his way to the door.

Initially baffled by the case, the Idaho Police Department seeks the help of the FBI, whose computer analysis of local surveillance videos identifies the killer’s (probable) car as a 2014-2016 white Hyundai Elantra. Soon after, a special taskforce of Idaho police and FBI agents extracts a tiny sample of “touch DNA” from the knife sheath dropped by the killer. From this, they build a genetic profile, which they upload onto commercial genetic genealogy websites, in hopes of tracing the killer through the sites’ millions of DNA family trees. This leads them to the grandparents of Bryan Kohberger, a graduate student living just ten miles from Moscow, who (they learn) owns a 2015 white Hyundai Elantra.

As Kohberger and his father drive from Pullman, Washington, to their Pennsylvania home, the FBI tracks them by both ground and air. Back home in Albrightsville, Pennsylvania, Bryan arouses his sister’s suspicions by sealing his personal trash into zip-lock bags while wearing surgical gloves, then disposing of them in a neighbor’s trashcan late at night. Local police, after stealing this trash and finding a DNA link to the killer, launch a massive SWAT team raid on the Kohberger house. Bryan Kohberger surrenders without incident, and in the months that follow, he calmly maintains his innocence. As the state announces its intention to seek the death penalty, Kohberger’s public defenders work diligently to build a compelling case for his innocence.

As yet, no firm date has been set for the trial, but Kohberger’s lawyers, with increasing confidence, have been picking away at the seemingly unassailable case against him. For example, “touch DNA”—the genetic evidence left on the knife sheath—is less reliable than other types of DNA. Also, the surveillance video of the killer’s car fails to show the driver’s face or license plate; the murder weapon is missing; the location pings of Kohberger’s cellphone, though suspicious, cannot definitively place him at the murder scene; and lastly, no evidence has been found to connect Kohberger to the victims prior to the murders, thus making his motive a mystery.

Nonetheless, in the book’s epilogue, Howard Blum opines that the many interlocking pieces of evidence, however flawed they may seem individually, cannot reasonably be dismissed as a mass of coincidences. As for motive, Blum surmises that Kohberger became murderously obsessed with Madison Mogen after meeting her at the restaurant where she worked. She alone, he argues, was his intended victim that night. However, only at the trial, which has been postponed several times, will these (and many other) questions be resolved—if they ever are. Meanwhile, the judicial gag order on the case has led to a free-for-all, flooding the internet with rumor, gossip, slander, and crackpot theories, increasing the pain and frustration for the victims’ families.