Chris Boudreau has been reeling for months after learning her son died fighting with a terrorist group overseas. Now, a self-proclaimed jihadist is urging the Calgary mother to embrace an extremist ideology she suspects was used to brainwash her son. On his blog, Abu Dujana al-Muhajir claims he was among a group of young men who left Calgary to join “various fronts of Jihad” after forming a study group at a downtown mosque. Damian Clairmont, Boudreau’s son who was also part of the group, was later killed during rebel infighting in Syria. Clairmont’s death devastated and confounded his mother, who...