Updated January 5, 2023 at 2:50 PM ET
Idaho authorities have released the most comprehensive evidence yet tying the stabbing deaths of four University of Idaho students to a suspect arrested last week and charged with murder in their killings.
Among the new information is the recovery of a DNA sample from a leather knife sheath found in one of the victims' beds that appears to be a strong match for Kohberger, as well as the revelation that a roommate of the victims had been awoken during the night and saw a strange masked man exit the house.
Idaho authorities have charged Bryan Kohberger with murder in the November stabbing deaths of the four students.
Kohberger, a 28-year-old criminology Ph.D. student at nearby Washington State University, has been charged with four counts of murder in the first degree, along with one count of felony burglary.
Early on the morning of Nov. 13, the four students — Ethan Chapin, 20; Madison Mogen, 21; Xana Kernodle, 20; and Kaylee Goncalves, 21 — were stabbed to death in the Moscow, Idaho, home where three of them lived together with two other students. The fourth victim, Chapin, was dating Kernodle and spending the night.
What the roommate told police
The hours before the attack had been a normal Saturday night of partying for the four victims, witnesses and friends say. Chapin and Kernodle had attended a fraternity party; Mogen and Goncalves had gone to a bar and stopped by a food truck on the way home to their house on King Road. All four were home by 2 a.m., and most were asleep by 4 a.m.
Two other roommates were not attacked. In an affidavit released Thursday, Moscow police said that one roommate, identified in the document as "D.M.," was awoken at approximately 4 a.m. by sounds coming from upstairs — including what she thought was her roommate Goncalves saying, "there's someone here."
D.M. looked out her bedroom door but didn't see anything, after which she heard more noises, she told investigators: crying, a male voice saying, "it's ok, I'm going to help you," more voices, a loud thud, a dog barking.
She opened her door again and this time saw "a figure clad in black clothing and a mask" walking toward her, the affidavit says.
It was a male stranger, she said, describing him as at least 5 feet, 10 inches, "not very muscular, but athletically built with bushy eyebrows."
As she "stood in a 'frozen shock phase,'" the man walked past her toward the house's rear sliding door, after which the roommate locked herself in her room, investigators said.
Police tracked car to and from the crime scene
Investigators also canvassed the area of the King Road house to collect video footage, which revealed a white sedan, later identified as a Hyundai Elantra, traveling toward the home around 3:30 a.m., making several passes by the house and then departing the area around 4:20 a.m. "at a high rate of speed."
Security footage from the campus of Washington State University in Pullman, Wash., where Kohberger is a graduate student, showed a similar white sedan headed in the direction of Moscow, about 15 miles away across the state line, shortly before 3 a.m. and then appearing to return around 5:30 a.m.
On Nov. 29, a police search of vehicles registered to WSU students revealed a 2015 white Hyundai Elantra registered to Bryan Kohberger, originally with Pennsylvania plates that were later registered in Washington.
Then, they tracked his cellphone
After identifying Kohberger as a possible suspect, police discovered that he had been subject to a traffic stop in August. At that time, he gave Moscow police his phone number.
In late December, investigators worked through cellphone records, attempting to uncover whether his phone had pinged cellphone towers near the crime scene or on routes to and from it.
An initial search showed that his phone did not, in fact, ping any cellphone towers near the crime scene on Nov. 13 between 3 a.m. and 5 a.m.
But investigators noted that a lack of cellphone pings could be "an effort to avoid alerting law enforcement" of one's proximity to a crime scene, they said.
Expanding their search, authorities discovered that Kohberger's phone pinged cell towers in Pullman around 2:47 a.m., consistent with the phone departing Kohberger's residence "and traveling south through Pullman," the affidavit says.
That was the last ping for about two hours, investigators said.
Then at 4:48 a.m., the phone appeared on the network again, pinging along highways south of Moscow, then west across the border into Washington state and then back north toward Pullman — a timeline that aligns with security footage of the white Elantra, investigators noted.
The disappearance of the phone from the network for two hours was consistent with an effort "to conceal his location during the quadruple homicide," the affidavit says.
There is no evidence in the affidavit that Kohberger's phone had been in contact with any of the victims or people associated with them.
But his phone had pinged cellphone towers in the area of the King Road house at least 12 times before the homicides, investigators found, including as early as Aug. 21, the day before his classes as a graduate student were set to begin at Washington State. Most of those occasions were late at night or early in the morning, the affidavit says.
The phone also returned to the area of the crime scene around 9:15 a.m. on Nov. 13, about five hours after the stabbings, before they had been reported to police.
Kohberger on the move
In mid-December, after the semester at Washington State had come to an end, Kohberger drove the Elantra back to his family's home in Pennsylvania, along with his father, who had traveled to Washington so the two of them could make the long drive together.
Investigators noted evidence of the car's journey back to Pennsylvania: a license plate capture in Colorado, a traffic stop in Indiana.
This week, authorities in Indiana released video of a pair of traffic stops along Interstate 70 east of Indianapolis, where two different officers had pulled over the Kohbergers for tailgating on the morning of Dec. 15.
Body camera footage shows the younger Kohberger driving the car with his father in the passenger seat. Both times, after a brief and polite conversation, the officers let the Kohbergers go without a ticket.
A possible DNA match
With a volume of evidence — the roommate's description, the movements of the white Elantra and the cellphone data — appearing to point to Kohberger, authorities in Idaho enlisted the help of Pennsylvania police to collect a DNA sample to test against the one recovered from the button snap of a tan leather knife sheath found in a bed near one victim's body.
On Dec. 27, police in Pennsylvania recovered a sample from the trash outside the Kohberger family residence in Albrightsville.
The Idaho state crime lab determined that the sample found in the trash likely belongs to the biological father of the person who left DNA on the knife sheath, according to the affidavit.
"At least 99.9998% of the male population would be expected to be excluded from the possibility of being the suspect's biological father," the affidavit says.
Three days later, Pennsylvania police arrested Kohberger. He was soon extradited to Idaho, where he is expected to appear in court on Thursday.
In an interview Tuesday, Kohberger's lawyer, Jason LaBar, the chief public defender of Monroe County, Pa., said the suspect "believes he's going to be exonerated."
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