Radicalisation of a promising student turned bomb maker in Brussels

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.

Laachraoui wheeled his handiwork into Brussels Airport on March 22 and, at age 24, blew himself up along with 15 bystanders, the authorities concluded after finding his DNA. Another attacker exploded a bomb nearby, and a third man detonated explosives on a subway, killing 17. The authorities suspect that bomb had also been made by Laachraoui.

Until that day, Laachraoui was an unseen yet central player and a crucial link between the cell that carried out the Paris attacks, organised by Abdelhamid Abbaoud, and the bombers in Brussels.

His journey from the Brussels neighborhood of Schaerbeek, where he grew up, to Syria - and back, as a changed and deadly man - is a trajectory decidedly different from that of many of his cohort, who were possessed of scant prospects and long rap sheets.

In the ruthless pecking order of the Islamic State, many of the others amounted to cannon fodder. But Laachraoui was no doubt a prized recruit: an educated European who radicalised all but invisibly, not in prison, but while in the classrooms of good schools and university study groups.

One former university acquaintance posted on Facebook a photograph of Laachraoui with seven other students in his electrical engineering class who had built a radio together. Laachraoui is dressed in Western clothes and stands in the back row, a sober look on his face.

Why the bomb maker would himself become a suicide bomber remains one of the essential mysteries surrounding him and, much like his radicalisation, defies simple explanation. In such cases, experts say, the environmental and circumstantial components can be pieced together. But the personal and psychological ones remain obscure.

One practical factor, experts speculate, is a frightening one: that Laachraoui was not the only Islamic State bomb maker in Europe, and perhaps not even the only one in Belgium. It is quite possible he learned his bomb-making skills from someone more experienced who has yet to be discovered.

The French and Belgian news media have reported that a man believed to be a Palestinian member of the Islamic State who has extensive bomb-making experience entered Europe shortly before the November 13 attacks in Paris.

Those who knew Laachraoui in high school say his latent radicalisation was hardly evident, though in retrospect perhaps there were some signs of alienation from his adopted Western culture.

Laachraoui was born on May 18, 1991, in Ajdir, Morocco, but he grew up in Belgium, according to court papers. By the time he was a young man, he was clearly grappling with what kind of Muslim he wanted to be.

"We are faced with a person who was in search of his Islam," said Bruno Derbaix, who taught a religion class at the Institut de la Sainte-Famille, where Laachraoui studied during high school.

© 2016 The New York Times News Service