The 27-year-old man photographed in 2009 seemed to represent hope springing from Paris’s desperate suburbs. Part of a work-insertion program, he was about to meet then-French president Nicolas Sarkozy, who was trying to combat high youth unemployment.... The man was Amedy Coulibaly, who was killed Friday after seizing hostages in a Jewish supermarket in Paris, an attack he claimed was in support of the terrorist Islamic State of Iraq & Al-Sham. A close associate of Said and Chérif Kouachi, the two brothers who attacked the satirical magazine Charlie Hebdo Wednesday, Coulibaly is a symbol of the huge challenges lying ahead...