WASHINGTON — An FBI employee has been indicted on charges that she stored classified documents and other national security information at home over the course of more than a decade, the Justice Department said Friday.

Kendra Kingsbury, 48, is accused of having unauthorized possession of a broad swath of sensitive government documents, including materials that describe FBI sources and methods and that contain information about operatives such as a suspected associate of Osama bin Laden.

Kingsbury worked as an intelligence analyst in the FBI’s Kansas City office for 12 years until her suspension in December 2017.

The two-count indictment, filed in the Western District of Missouri, alleges that Kingsbury stored the materials at home between 2004 and 2017. It does not provide a reason for why Kingsbury mishandled the documents, and the Justice Department declined to elaborate beyond the indictment on Friday.

“The breadth and depth of classified national security information retained by the defendant for more than a decade is simply astonishing,” Alan E. Kohler Jr., the assistant director in charge of the FBI’s Counterintelligence Division, said in a statement.

The case underscores the risk to national security posed by “insider threats,” said Assistant Attorney General John Demers, the Justice Department’s top national security official.

Court documents do not identify a lawyer for Kingsbury, of Dodge City, Kansas. A message left at a phone number connected to her was not immediately returned.