Authorities have identified one of the al-Shabab gunmen responsible for the massacre last week at a Kenyan university that killed 148 students as the son of a Kenyan official. A chief in Mandera County had reported his son missing last year, fearing that he had gone to Somalia to join al-Shabab. His worst fears were confirmed Sunday, when his son, Abdirahim Mohammed Abdullahi, was named as one of the gunmen in the attack at Garissa University College on Thursday. Security forces killed all the four attackers.

Abdullahi had graduated from the University of Nairobi with a law degree in 2013. A Garissa-based official who did not want to be named told the news agency Reuters that Abdullahi had joined the Islamist militant group after graduating. “He was a very brilliant student. But then he got these crazy ideas,” the official said.