A suspect was arrested Friday in Pennsylvania on an active arrest warrant for murder in the first degree in connection with the killings of four University of Idaho students last month, documents and sources say.
The man arrested is Bryan Christopher Kohberger, 28, according to the criminal complaint. He was taken into custody Friday in Monroe County, the document states.
Authorities narrowed their focus to Kohberger after tracing his ownership of a white Hyundai Elantra seen in the area of the killings, according to two law enforcement sources briefed on the investigation. Kohberger's DNA has also been matched to genetic material recovered at the off-campus house where the students were stabbed to death, according to the sources.
Authorities learned the suspect had left the area and went to Pennsylvania, the sources said.
An FBI surveillance team from the Philadelphia field office has been tracking him for four days in the area where he was arrested, according to the sources.
While he was being watched, investigators from the Moscow Police Department, the Idaho State Police homicide bureau, and the FBI worked with prosecutors to develop sufficient probable cause to obtain the warrant. Once the arrest warrant was issued, the Pennsylvania State Police and the FBI made the arrest.
More details are expected to be released when the Moscow Police Department holds a news conference that is scheduled for 1 p.m. (4 p.m. ET).
Records show Kohberger was arraigned Friday morning in Pennsylvania and he has a court hearing on extradition January 3.
Suspect is graduate student at nearby university
Kohberger is a graduate student at Washington State University's Department of Criminal Justice and Criminology, according a now-removed university graduate directory. A CNN team in Pullman, which is only 7 miles from Moscow, saw law enforcement activity at an apartment complex where graduate students live.
In a post removed from Reddit after Kohberger's arrest was made public, a student investigator associated with a DeSales University study named Bryan Kohberger sought participation in a research project "to understand how emotions and psychological traits influence decision-making when committing a crime."
"In particular, this study seeks to understand the story behind your most recent criminal offense, with an emphasis on your thoughts and feelings throughout your experience," the post said.
One of the principal investigators of that study, a professor at DeSales University, in Pennsylvania, declined to comment on the matter.
Officials at Washington State University haven't responded to CNN's request for comment.
Case shocked small college town
The November 13 killings riveted the nation and shocked the small college town of Moscow, its first murder in seven years. The case prompted fear and anxiety in the community and student body, and questions mounted about the pace of the police investigation.
The arrest comes a day after police said they have received about 20,000 tips through more than 9,025 emails, 4,575 phone calls, and 6,050 digital media submissions, while having conducted over 300 interviews.
The slain students -- Kaylee Goncalves, 21; Madison Mogen, 21; Xana Kernodle, 20; and Kernodle's boyfriend, Ethan Chapin, 20 -- were likely asleep when they were each stabbed multiple times in the early morning hours, authorities have said. Some of the victims had defensive wounds, a coroner has said.
Police have said they were searching for the Elantra thought to have been near the home early on November 13.
The home where the killings occurred will be cleaned up but remain an active crime scene under police control, authorities said Thursday.
Moscow police say they have worked with a property management services company to remove "potential biohazards and other harmful substances used to collect evidence," the update said. The home will be turned over to the property management company.
