He was part of an Islamic Awareness circle at Umar ibn Abd al-Aziz Mosque in Khobar, where one of the instructors was al-Ayiri.

At 16, he travelled to Bosnia to participate in the Bosnian War with Khaled Ali Hajj, a friend from the circle who had returned from fighting in Afghanistan.

[4] Just before the end of the war he was recruited by Khalid Sheikh Mohammed, who suggested that he go to Afghanistan and give him a contact in Peshawar, Pakistan.

He researched the fatwa which was about the Mongol invasion and their use of human shields when besieging cities;[6] it was clear to him that this was no justification for killing civilian bystanders.

Dean planned to leave the UK, where he had been granted permanent residence, with his family to find a school for his children in the Middle East.