Bryan Kohberger is escorted to an extradition hearing at the Monroe County Courthouse in Stroudsburg
Bryan Kohberger, who is accused of killing four University of Idaho students, is escorted to an extradition hearing at the Monroe County Courthouse in Stroudsburg, Pennsylvania, U.S., January 3, 2023. Matt Rourke/Pool via REUTERS Reuters

A woman who lived at the house where four University of Idaho students were stabbed to death told investigators she was awakened on the night of the murders by the sound of someone crying in one of the victim's bedrooms - and then watched as a masked man walked past her and out of the house.

The harrowing detail was included in a newly unsealed affidavit on Thursday, just before Bryan Kohberger, the 28-year-old doctoral student charged with the November slayings, made his first court appearance in Moscow, Idaho.

The document also said police have linked Kohberger to the murders using DNA, cell phone data and video footage.

The woman, one of two roommates who were left unharmed, told authorities she stood in "frozen shock" shortly after 4 a.m. on Nov. 13 as the man, clad in black, passed by her, before she locked herself in her room.

Kohberger, who has been working towards a criminal justice PhD degree at Washington State University, about 10 miles (16 kilometers) from the University of Idaho campus in Moscow, faces four counts of first-degree murder and burglary.

He wore an orange jump suit in court and answered "yes" to several questions the judge asked regarding whether he understood the charges against him. He did not enter a plea and will be held without bail.

A status hearing was scheduled for Jan. 12.

Kohberger was arrested in Pennsylvania last week, where he was visiting his family, and flown to Idaho on Wednesday.

Investigators were able to match DNA recovered from a knife sheath left at the scene with DNA taken from trash at the Kohberger family residence, according to the unsealed affidavit, written by Moscow Police Corporal Brett Payne.

Video footage captured a white Elantra, similar to a car registered to Kohberger, passing the house three times on the night of the murders before the driver attempted to park, Payne wrote. About 15 minutes later, the car was seen leaving at a "high rate of speed."

A Washington State University officer identified Kohberger as the owner of a similar car.

Tracking data showed Kohberger's cell phone appeared to leave the WSU campus around 2:45 a.m. on the night of the attack before going dead for around two hours then reappearing south of Moscow and eventually moving towards his campus home, the affidavit said.

The period of time when the phone was not detected is "consistent with Kohberger attempting to conceal his location," the affidavit said.

The crime stunned the small college town in northwestern Idaho. The victims - Ethan Chapin, 20, of Conway, Washington; Xana Kernodle, 20, of Avondale, Arizona; Madison Mogen, 21, of Coeur d'Alene, Idaho; and Kaylee Goncalves, 21, of Rathdrum, Idaho - all suffered multiple stab wounds, according to authorities. Chapin was Kernodle's boyfriend.

Payne did not suggest a motive for the attack or any connection between Kohberger and the victims.

In a survey posted on the social media site Reddit, Kohberger asked participants to help "understand how emotions and psychological traits influence decision making when committing a crime," the affidavit said.