An 33-year-old American from San Diego was killed over the weekend while fighting for the Islamic State of Iraq and al-Sham, according to the Free Syria Army. Photos of Douglas McAuthur McCain’s passport and his body — which featured a distinctive neck tattoo — have been seen by NBC News. McCain attended high school in Minnesota. A woman who said she was McCain’s aunt confirmed to NBC News that he had passed and referred calls to his mother. Click through for more on McCain's background.