A graduate student has been accused of fatally stabbing a 77-year-old Binghamton University anthropology professor.

Authorities say Abdulsalam al-Zahrani was charged with murder Saturday in the death of Richard T. Antoun on Friday.

Broome County District Attorney Gerald Mollen says Antoun knew al-Zahrani from school. He told The New York Times the two had known each other for "quite some time."

Mollen says he didn't know whether al-Zahrani has an attorney. There was no phone listing in Binghamton for the 46-year-old Saudi national.

Antoun has written several books, including "Understanding Fundamentalism: Christian, Islamic, and Jewish Movements."

Mollen says there's no indication of religious or ethnic motivation in the attack.