A PhD student in criminology at Washington State University has been arrested and charged with first-degree murder

in the stabbing deaths of four University of Idaho students more than six weeks ago, police said. The 28-year-old suspect was charged with first-degree murder in the stabbing deaths of the students.

Bryan Christopher Kohberger, 28, was arrested on Friday in the state of Pennsylvania, said James Fry, chief of police in the town of Moscow, Idaho, where the university is located.

Kohberger was charged with four counts of first-degree murder and felony burglary, said  prosecutor Bill Thompson of Latah County, Idaho.

The four victims – three women and a man in their early 20s – were found fatally stabbed on the morning of November 13 inside an off-campus house where the three women lived.

The fourth killed was the boyfriend of one of the roommates. The quadruple killings sent shockwaves through the small college town.

Two other female roommates in the house at the time were unharmed, apparently sleeping through the killings.

Police said the cellphone of one of the survivors was used to call emergency-911 when the bodies were first discovered.