In all, the gunman had owned 14 firearms, said Celinez Nunez, an agent of the Bureau of Alcohol, Tobacco, Firearms and Explosives, including one he had traded in. The Douglas County Sheriff’s Department said the gunman took five handguns and a rifle to Umpqua Community College on Thursday morning, and had two pistols, four rifles and a shotgun in his apartment.

“All 14 have been traced to a federal firearms dealer,” some bought by the gunman and others by members of his family, said Ms. Nunez, the assistant special agent in charge of the Seattle field office. “They were all purchased legally.”