[EDVA] Sean Andrew Duncan of Sterling, Va., has been charged with attempting to obstruct a terrorism investigation. Duncan is alleged to have tried to get rid of a thumb drive and memory chip he destroyed when federal agents came to search his home. Court documents allege Duncan may have converted to Islam and become interested in joining the Islamic State (ISIS) and carrying out an attack in the U.S. Duncan also deleted his Facebook account and changed his phone number after he was interviewed by the FBI and barred from entering Turkey. Court records also said that Duncan possessed a smartphone containing child pornography images. He pleaded guilty to obstructing a counterterrorism investigation and receipt of child pornography and was sentenced to 20 years in prison, to be followed by a lifetime of supervised release.