Bryan Kohberger, the 28-year-old suspect, is back in Idaho to face charges.
BOISE, Idaho -- One of the roommates who survived the quadruple murders at the University of Idaho told authorities she saw a man in black clothes and a mask walking past her in her house on the night of the killings, and she stood "frozen" and in "shock," according to newly released court documents.
The roommate said she didn't recognize the man, who walked toward the back sliding glass door at her off-campus home in Moscow, Idaho, in the early hours of Nov. 13, according to documents. She locked herself in her room after seeing the man, the documents said.
She described the intruder as 5-foot-10 or taller, and "not very muscular, but athletically built with bushy eyebrows," according to the documents.
Two roommates -- who police said are not suspects -- survived. On the morning of Nov. 13, the two roommates called friends over to their house because they thought one of the victims on the second floor had passed out and wasn't waking up, police said. Around noon, a 911 call from one of the roommate's phones requested help for an unconscious person, police said.
Responders found University of Idaho students Xana Kernodle, Kaylee Goncalves, Madison Mogen and Ethan Chapin all stabbed to death.
The mysterious slayings went unsolved for weeks and garnered national interest. The 28-year-old suspect, Bryan Kohberger, was arrested in his home state of Pennsylvania on Friday and was extradited to Idaho on Wednesday.
Authorities say DNA from the suspect was recovered on a tan leather knife sheath left on Mogen's bed, according to the documents. On Dec. 27, police recovered trash from Kohberger's parents' house in Pennsylvania, and a lab then determined that the DNA from the trash was the father of the person who left DNA on the knife sheath, the affidavit said.
Police believe the murders unfolded between 4 a.m. and 4:25 am., according to the newly released court documents.
Kernodle got a DoorDash order at the house at about 4 a.m., according to the affidavit.
One of the surviving roommates said she woke up around 4 a.m. from what sounded like Goncalves playing with her dog in one of the third floor bedrooms, according to the affidavit.
"A short time" after, the roommate said "she heard who she thought was Goncalves say something to the effect of 'there's someone here,'" the documents said. But that could have been Kernodle on her phone because records showed she was on TikTok at about 4:12 a.m., the affidavit said.
The roommate said "she looked out of her bedroom but did not see anything when she heard the comment about someone being in the house," the documents said. "She opened her door a second time when she heard what she thought was crying coming from Kernodle's room."
The roommate "then said she heard a male voice say something to the effect of 'it's ok, I'm going to help you,'" according to the documents.
The roommate said she opened her door again when she heard the crying, and that's when she saw the figure in the mask, the documents said.
A shoe print believed to be from the intruder was found outside one of the survivors' rooms, the documents said.
At about 4:17 a.m., a security camera less than 50 feet from Kernodle's room picked up sounds of a barking dog and "distorted audio of what sounded like voices or a whimper followed by a loud thud," according to the documents.
After the victims were discovered, authorities reviewed surveillance video from the area and saw the suspect's white Hyundai Elantra go by the victims' house three times, before entering the area for a fourth time at 4:04 a.m, according to the documents.
Police said they traced the car's travel that night back to nearby Pullman, Washington, where the suspect lived while attending Washington State.
Kohberger was a Ph.D. student in Washington State's department of criminal justice and criminology at the time of the murders. Washington State's campus is less than 10 miles from Moscow, Idaho.
Moscow police asked law enforcement to look out for white Elantras, the affidavit said, and on Nov. 29, a Washington State University police officer searched cars that matched that description at the university and found one registered to Kohberger.
Kohberger's phone was tracked heading to Moscow before the attack and as the driver of the white Elantra returned to Pullman. However, the phone was off from 2:47 a.m. to 4:48 a.m., which "is consistent with Kohberger attempting to conceal his location during the quadruple homicide," the document said.
His phone was near the victims' house at least 12 times before the murders, including as far back as August, the document said. All of those times, except for one, were late at night or early in the morning.
The morning after the murders, he went near the house between 9:12 a.m. and 9:21 a.m., the documents said, citing cellphone data.
Kohberger also registered his white Elantra in Washington state on Nov. 18 -- five days after the murders -- and received a new license plate, according to the documents. The car had previously been registered in Pennsylvania and his Pennsylvania plate was set to expire on Nov. 30.
Police said they learned Kohberger applied for an internship with the Pullman police in the fall of 2022, and in an essay he said he wanted to help "rural law enforcement agencies with how to better collect and analyze technological data in public safety operations," the affidavit said.
"Kohberger also posted a Reddit survey which ... asked for participants to provide information to 'understand how emotions and psychological traits influence decision making when committing a crime,'" the affidavit said.
Kohberger appeared in court in Monroe County, Pennsylvania, on Tuesday on the first-degree murder and burglary charges and agreed to be extradited to Idaho.
His parents and two sisters attended the Pennsylvania hearing and Kohberger mouthed the words "I love you" to his family as he was escorted away.
Kohberger's attorney in Pennsylvania, Monroe County Chief Public Defender Jason LaBar, said in a statement his client was "eager to be exonerated of these charges and looks forward to resolving these matters as promptly as possible."
Moscow police said Tuesday night that an Idaho judge has issued a nondissemination order in the case
"The order prohibits any communication by investigators, law enforcement personnel, attorneys, and agents of the prosecuting attorney or defense attorney concerning this case," police said. "Due to this court order, the Moscow Police Department will no longer be communicating with the public or the media regarding this case."
ABC News' Luke Barr, Kayna Whitworth, Jenna Harrison and John Capell contributed to this report.