CNN
 — 

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.

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…