Crime Serial Killers Chilling Details Revealed as Probable Cause Affidavit is Released in University of Idaho Murder Case On Dec. 30, authorities announced that Bryan Kohberger, 28, was charged with four counts of murder in connection with the stabbing deaths of four University of Idaho students By Corin Cesaric Corin Cesaric Corin Cesaric is an Associate Editor at PEOPLE. She has been working at PEOPLE for more than two years. People Editorial Guidelines Published on January 5, 2023 12:39PM EST The shocking killings of four University of Idaho students left the town of Moscow, Idaho on edge for nearly seven weeks while authorities searched for a killer. On Friday, after remaining tight-lipped over the course of the initial investigation, authorities announced that Bryan Kohberger, 28, was arrested in Pennsylvania and charged with four counts of murder and one count of felony burglary in connection with the stabbing deaths of Madison Mogen, 21, Kaylee Goncalves, 21, Xana Kernodle, 20, and Ethan Chapin, 20. Suspect Arrested in Killings of Four University of Idaho Students On Jan. 3, Kohberger waived his extradition, and he was transported to Idaho on Jan. 4. His next hearing is scheduled for Jan. 12. Now that he is back in Idaho, the probable cause affidavit has been released, shedding light on what led investigators to arrest Kohberger. According to the affidavit, which has been reviewed by PEOPLE, a sheath of the knife used in the stabbings was left at the scene in the bed where Mogen and Goncalves were found deceased. This is where detectives found DNA linking Kohberger, according to the affidavit. Agents took trash from Kohberger's parents' home in Pennsylvania to test for a DNA match, the documents allege. For more on this story, listen below to our daily podcast PEOPLE Every Day. According to the affidavit, one of the surviving roommates said they saw the killer, described in the affidavit as "a figure clad in black clothing and a mask," who walked past her as he left the crime scene, and she heard crying on the night of the killings. Kohberger was linked to the crime scene from DNA and cell phone pings, the affidavit alleges. Idaho Murder Victims' Families React to Suspect's Arrest: 'Such a Blessing and Relief' Ethan Chapin, Madison Mogen, Kaylee Goncalves and Xana Kernodle. Around 4:20 a.m., a white sedan referred to as "Suspect Vehicle 1" in the affidavit was seen leaving the area of the home at a fast rate of speed, the affidavit alleges. According to the document, the vehicle and phone associated with Kohberger returned to the scene between 9:12 a.m. and 9:21 a.m. While investigating previous cellphone pings, authorities learned that the cell phone associated with Kohberger pinged in the area of the 1122 King Road home where the killings took place on at least twelve occasions prior to November 13, 2022, the affidavit alleges. "All of these occasions, except for one, occurred in the late evening and early morning hours of their respective days," the affidavit reads. Bryan Kohberger on Jan. 3, 2023. Matt Rourke/AP/Shutterstock At the time of the slayings, Kohberger was a Ph.D student at Washington State University studying criminal justice and criminology. The university, which is in Pullman, Wash., is approximately eight miles away from the residence in Moscow, Idaho where the four students were killed. A white Hyundai Elantra — which is the same vehicle authorities were searching for in connection with the case — was taken from the Kohberger family home on the day of the suspect's arrest. Suspect in U of I Killings Allegedly Researched What It Was Like to Commit Crimes, Studied Criminology Goncalves, Mogen, Kernodle, and Chapin — who were all close friends and students at the University of Idaho — were stabbed to death on the second and third floors of the off-campus residence in the early morning hours of Nov. 13. Two additional roommates were home during the attack but were unharmed. Early in the investigation, the surviving roommates were ruled out as suspects. Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases. It was previously reported that the two surviving roommates both slept through the attack on the first floor of the residence, but the affidavit states that one of the roommates was on the second floor where Kernodle and Chapin were killed. Kernodle received a DoorDash order around 4 a.m. and was on TikTok on her phone at 4:12 a.m., the affidavit alleges. Goncalves, Mogen, and Kernodle were roommates and Chapin was staying the night with Kernodle, his girlfriend. A motive for the killings has not been released at this time. Surviving Roommates of Slain University of Idaho Students Break Silence In a statement on Friday, Moscow Mayor Arthur D. Bettge thanked law enforcement for their work on the case that shocked the nation. "I understand that law enforcement's inability to share information during the course of the investigation has been frustrating, but their primary duty was to protect the integrity of the investigation and find a resolution to the case for the victims and their families," the statement reads, in part. "I hope this arrest and subsequent criminal justice system process will begin to provide comfort and closure to the victim's families, our community, and the nation." The Moscow Police Department is asking anyone with information about the killings or Bryan Kohberger to call 208-883-7180 or email tipline@ci.moscow.id.us.