A 46-year-old Binghamton University graduate student from Saudi Arabia was charged on Saturday with killing a retired anthropology professor, a specialist in Islamic and Middle Eastern studies with whom he had worked, the authorities said.

The student, Abdulsalam S. al-Zahrani, was charged with second-degree murder in the death of the professor, Richard T. Antoun, who was stabbed in his office in the university’s Science I building on Friday afternoon, said Gerald F. Mollen, the district attorney in Broome County. “We believe the murder weapon was recovered,” he said.

Mr. Mollen said in a statement that Mr. Zahrani and Professor Antoun had known each other through Mr. Zahrani’s “work in the graduate program.” Later, in an interview, the district attorney said that “they’ve known each other for quite some time.” The extent of their contact was not immediately clear.

Mr. Zahrani, a citizen of Saudi Arabia who is a graduate student in anthropology, was being held without bail at the Broome County Sheriff’s Correctional Facility after his arraignment in Town Court in Vestal, N.Y., Mr. Mollen said.