Adam Stuart Busby, 64, of Dublin, Ireland, was charged Wednesday with 17 emailed threats sent to the school between April 6 and 21, and also with emailed bomb threats against federal courthouses in Pittsburgh, Erie and Johnstown in June.
He's also charged with threatening Pittsburgh-based U.S. Attorney David Hickton - who led the investigation that resulted in Busby's indictment - in a June 20 email.
Busby is in custody in Ireland. It wasn't clear when he'd be brought to Pittsburgh to face the charges.
He has no known ties to Pittsburgh or the university.