Idaho murders: Bryan Kohberger applied for internship at Pullman Police Department in fall 2022

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.

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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. 

"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.

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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. 

Idaho murders: Bryan Kohberger changed license plate five days after student slayings

The suspect in the grisly murders of four University of Idaho students switched his license plate five days after his car was spotted near the crime scene, according to state records and a newly unsealed case filing.

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.

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.