A video released by the Islamic State on Tuesday evening shows a young boy executing an Arab-Israeli man who identifies himself as 19-year-old Mohammed Said Ismail Mussallam. He kneels in front of the young boy, who appears to be no older than 10 years old. The boy stands over the hostage who wears an orange jumpsuit. He shoots the man in the head and shouts “Allahu Akbar” (God is Greatest) and then shoots the already dead man four times.

Last month, Mussallam’s father denied allegations that his son was spy who had been allegedly recruited by Israeli intelligence.

Warning: Scenes in the 13 minute video are horrific.