Idaho suspect Bryan Christopher Kohberger is on his way to Moscow to face charges for the murders of four University of Idaho students

Kohberger, 28, left Monroe County Correctional Facility in Pennsylvania, according to Warden Garry Haidle.

 "He is no longer in my custody," Haidle said. "He is in the custody of the Pennsylvania State Police."

Alexis McAdams that Idaho and Pennsylvania authorities are working together on returning him to Moscow.

He was slated to fly out this morning, but it wasn't immediately clear if he already boarded the plane, the sourced added.

The Washington State University Ph.D. student waived extradition at a hearing in Monroe County Court Tuesday afternoon.

Judge Margherita Worthington asked Kohberger in court as his distraught parents and two sisters looked on from the gallery if he waived his right to challenge his arrest for the quadruple homicide.

"Yes, I do," he replied, wearing a red jail-issue jumpsuit and shackles on his wrists. Kohberger was arrested by local police and the FBI Friday at his parents' home in Albrightsville, Pennsylvania.

The teaching assistant, who studies in the university's department of criminal justice and criminology, had been living in Pullman, Washington

an on-campus apartment – a 10-minute drive from the rental home where four University of Idaho students were stabbed to death.