It was a case of instant captivation when Shagari first heard Boko Haram¡¯s founder deliver a jihadi sermon a decade ago.

Gripped by the message, Shagari swapped life as a father and electrician to join the militants and rose rapidly through their ranks, his ascent mirroring the group¡¯s own growing stature.

He took easily to the extremism and brutality.