Bryan Kohberger leaves after an extradition hearing at the Monroe County Courthouse in Stroudsburg
Reuters

Court documents unsealed Thursday show police using DNA, cell phone data and surveillance footage to identify and then arrest the 28-year-old man suspected of murdering four University of Idaho students.

The affidavit seeking the arrest of Bryan Kohberger stated that one of the surviving roommates heard a victim crying and a masked man leave the residence shortly after committing the murders.

A roommate, identified as D.M. in the affidavit, told police she had awoken around 4 a.m. on Nov. 13 to what she assumed was Kaylee Goncalves playing with her dog on the third floor of the home.

A short time later, she thought she heard one of the victims say, "there's someone here."

D.M. looked out of her bedroom following the comment but didn't see anything. She said she heard crying coming from Xana Kernodle's room.

D.M. then heard a male's voice say, "It's ok, I'm going to help you." After hearing the crying, she opened the door and saw a masked figure walking toward her.

D.M. described the figure as "5'10" or taller, male, not very muscular, but athletically built with bushy eyebrows."

D.M. stood in a "frozen shock phase" as the male walked past her toward the back sliding glass door. She told investigators she locked herself in her bedroom and did not recognize the male.

Authorities suspected Kohberger as the culprit after finding DNA on a knife sheath found at the crime scene, surveillance video showing his car in the neighborhood and cell phone data tracking his whereabouts and showing him to me near the scene at the same time as the murders. Investigators say photographs of Kohberger show he sported bushy eyebrows.

Kohberger is charged with killing Goncalves, 21; Madison Mogen, 21; Ethan Chapin, 20; and Kernodle, 20.

Kohberger faces four counts of first-degree murder and one count of felony burglary. The suspect appeared in court on Thursday following his extradition to Idaho from Pennsylvania, where he was arrested.

He was held without bail and prohibited from contacting the surviving roommates or victims' families. Kohberger's next hearing is scheduled for Jan. 12.