Authorities tracked the Idaho student killings suspect as he drove cross-country to Pennsylvania, sources say

Authorities carefully tracked the man charged in the killings of four Idaho college students as he drove across the country around Christmas and continued surveilling him for several days before finally arresting him Friday, sources tell CNN.

Bryan Christopher Kohberger, 28, was arrested in his home state of Pennsylvania and charged with four counts of murder in the first degree, as well as felony burglary in connection with the stabbing deaths of four University of Idaho students in November, according to Latah County Prosecutor Bill Thompson.

Kaylee Goncalves, Ethan Chapin, Xana Kernodle and Madison Mogen were killed November 13 off campus at the University of Idaho.

Still, investigators have not publicly confirmed the suspect’s motive or whether he knew the victims. The murder weapon has also not been located, Moscow Police Chief James Fry said Friday.

In the nearly seven weeks since the students were found stabbed to death in an off-campus home, investigators have conducted more than 300 interviews and scoured approximately 20,000 tips in their search for the suspect. News of the killings – and the long stretch of time without a suspect or significant developments – have rattled the University of Idaho community and the surrounding town of Moscow, which had not seen a murder in seven years.

Investigators honed in on Kohberger as the suspect through DNA evidence and by confirming his ownership of a white Hyundai Elantra seen near the crime scene, according to two law enforcement sources briefed on the investigation.

Kohberger, who authorities say lived just minutes from the scene of the killings, is a PhD student in Washington State University’s Department of Criminal Justice and Criminology, the school confirmed.

He drove cross-country in a white Hyundai Elantra and arrived at his parents’ house in Pennsylvania around Christmas, according to a law enforcement source. Authorities were tracking him as he drove and were also surveilling his parents’ house, the source said.

An FBI surveillance team tracked him for four days before his arrest while law enforcement worked with prosecutors to develop enough probable cause to obtain a warrant, the two law enforcement sources said.

Genetic genealogy techniques were used to connect Kohberger to unidentified DNA evidence, another source with knowledge of the case tells CNN. The DNA was run through a public database to find potential family member matches, and subsequent investigative work by law enforcement led to him as the suspect, the source said.

What happens next

Kohberger was arraigned Friday morning in Pennsylvania and is being held without bail pending his extradition hearing on January 3, records show.

The suspect has the option to waive extradition and return to Idaho voluntarily. But if he chooses not to, Moscow police will have to initiate extradition proceedings through the governor’s office, which could take some time, Fry said.

Even with a suspect charged, law enforcement’s work is far from over, prosecutors said.

“This is not the end of this investigation. In fact, this is a new beginning,” Thompson said Friday night.

-cnn