El-Hussein swore fidelity to ISIS leader Abu Bakr al-Baghdadi in a posting made on what was apparently his Facebook page just before the shooting spree began Saturday . Author and journalist who met the boy says he grew up in a hardcore gang environment . Al - Hussein was kicked out of the gang and appears to have turned to Islam , he said .
Author and journalist who met the boy says he grew up in a hardcore gang environment . Al - Hussein was kicked out of the gang and appears to have turned to Islam , he said .