A US military serviceman has been arrested after concerns were raised that a possible second attack could occur on Fort Hood, Fox News reports. Pvt. Nasser Jason Abdo, a soldier from Fort Campbell who went AWOL on July 4, was arrested near Fort Hood. Authorities won't say whether he is the person who raised their concerns; one source says two other soldiers raised concerns. A Fort Campbell spokesperson says Abdo is being investigated for child porn, while another source tells Fox News Abdo had explosives and jihadist literature in his possession when he was arrested. (More Fort Hood stories.)