Radicalization of a Belgium Student Turned Bomb Maker Was Invisible

Najim LaachraouiBRUSSELS — He attended Catholic school and studied electrical engineering. His immigrant family valued education and discipline. His brother carries the Belgian flag as a national martial arts champion.

But none of that stopped Najim Laachraoui from being drawn to the Islamic State, or from turning the technical skills that could have provided a bright future to building the bombs that, the authorities suspect, were used in the recent attacks in Paris and Brussels.