Idaho murders: Bryan Kohberger applied for internship at Pullman Police Department in fall 2022
Idaho murder latest: Suspect appears in court for the first time, court documents shed light on night of murders
Newly obtained court documents reveal how authorities used DNA and cell phone records to link suspect Bryan Christopher Kohberger to the brutal killings of four University of Idaho students.
MOSCOW, Idaho - Brian Kohberger, the criminology Ph.D. student accused of stabbing four University of Idaho students to death in November, applied for an internship in the fall with the local police department in Pullman, Washington, according to a newly released probable cause affidavit.
Kohberger worked as a teaching assistant at Washington State University and lived in Pullman, a college town just miles from the crime scene in Moscow, Idaho.
He submitted his application to the police department at some point during the fall semester, when he took his first semester of classes at WSU after graduating from DeSales University with a master’s degree in psychology and cloud-based forensics in June 2022.
DNA, cell phone data used to identify suspect in Idaho murders
Bryan Kohberger has been arrested and extradited back to Idaho to face charges in connection to the brutal killings of four University of Idaho students. Court documents reveal what helped identify him as a suspect, and a former homicide detective gives his take on Kohberger's psyche with the limited information provided in the documents.
"Kohberger wrote in his essay he had interest in assisting rural law enforcement agencies with how to better collect and analyze technological data in public safety operations," an arrest affidavit states.
TIMELINE: What we know about the violent quadruple murder in Moscow
A spokesperson for the Pullman Police Department could not immediately be reached for comment about the application.
As part of his graduate studies at WSU, Kohberger also posted a survey on Reddit, asking prospective participants to provide information about "how emotions and psychological traits influence decision making when committing a crime," according to the affidavit.
Read the affidavit below (Warning: graphic content):
While at DeSales University, he studied under an expert on serial killers, Dr. Katherine Ramsland, who co-wrote a book with the BTK Killer, Dennis Rader.
Kohberger received an associate's degree from Pennsylvania's Northampton Community College before studying at DeSales and WSU.
A former friend of Kohberger from Northampton, Pennsylvania, who asked to remain anonymous because of her job, said she does not believe Kohberger wanted to be a police officer, but that he was interested in studying crime.
"He was very interested in psychology and, you know, criminology and things like that. So he was very interested in kind of the way the mind works," the friend told Fox News Digital. "Just people in general, what makes things tick."
Kohberger’s interest in law enforcement dates to his younger years at Pleasant Valley High School in Pennsylvania, when he also aspired to enter the military. A yearbook from 2011 shows Kohberger in a law enforcement class doing push-ups with a badge dangling from his left pocket.
The yearbook said Kohberger used the class to "help him reach his goal to one day serve in the Army Rangers," an elite special operations force.
Kohberger was arrested Dec. 30 at his parents' home in Albrightsville, Pennsylvania, and extradited to Idaho Wednesday, where he is facing four counts of first-degree murder and a felony burglary charge.
Idaho murders: Watch Bryan Kohberger's first court appearance in Moscow (full video)
Slain University of Idaho victims' roommate heard crying and saw the alleged killer clad in all black the morning of the mass murder, according to newly unsealed court documents. Bryan Kohberger first court appeared in a Latah County, Idaho courtroom on Jan. 5. He is being held with no bail and faces four counts of first-degree murder and one count of burglary for entering the home.
Authorities allege Kohberger broke into an off-campus apartment near the University of Idaho in the early morning hours of Nov. 13 and murdered Kaylee Goncalves, 21, Maddie Mogen, 21, Xana Kernodle, 20 and Ethan Chapin, 20.
He allegedly left behind a tan leather knife sheath that had "Ka-Bar" and the United States Marine Corps eagle globe and anchor stamped on it, according to the affidavit. Investigators wrote that they found DNA belonging to Kohberger on the sheath.
Fox News' Chris Eberhart, Michael Ruiz, Stephanie Pagones and Audrey Conklin contributed to this report.