 While serving a sentence for firearms possession at the Österåker Prison in 1998, he shared cell with Oussama Kassir, a militant Islamist charged with terrorism who has said that he "loves al-Qaeda and Osama bin Laden".Kassir said he became close friends with Chatty and was instrumental in his conversion to Islam.According to BBC News he was "believed to have become" a devotee of the Salafi school of Islam.