(NewsNation) — Police identified Bryan Kohberger, the 28-year-old criminal justice graduate student accused of killing four University of Idaho students, through a combination of DNA evidence at the scene, cell phone records and Kohberger’s white Hyundai Elantra, according to a newly unsealed probable cause affidavit.

The court records — which became available Thursday morning after alleged killer Bryan Christopher Kohberger arrived in Idaho — reveal the justification authorities used to obtain a warrant for Kohberger’s arrest.

Scroll to the bottom of the article to read the full affidavit.

Investigators linked the 28-year-old suspect to the crime scene after finding a “tan leather knife sheath” laying next to victim Madison Mogen’s bed, according to the affidavit.

“The Idaho state lab later located a single source of male DNA left on the button snap of the knife sheath,” the document reads. Authorities were able to link that DNA to Kohberger.

In the early hours of November 13, before the victims were discovered, investigators say one of the surviving roommates opened her door after she heard crying and “saw a figured clad in black clothing that covered the person’s mouth and nose walking towards her.”

The man then walked past her toward a sliding glass door. The witness described the figure as “5’10” or taller, male, not very muscular, but athletically built with bushy eyebrows,” the affidavit says.

After seeing the figure, the witness went back into her room and locked the door. She did not say that she recognized the male, investigators said.

Law enforcement later determined that Kohberger matched the description the surviving witness provided.

Read the full affidavit below:

This story is developing and will continue to be updated.