A White House Correspondents' Dinner volunteer, Helen Mabus, revealed that the suspected gunman appeared to have assembled a long weapon in an unsecured room near the terrace-level entrance and then opened fire near the ballroom. Mabus said the suspect was partially out of view of security as he handled the weapon inside the room before moving towards the main event space. The gunman then began shooting in multiple directions as guests and staff scrambled for their escape.