HORSE. BARN. DOOR:

Officials at the National Archives were so concerned about Samuel R. Berger’s removal of classified documents last year that they imposed new security measures governing the review of sensitive material, including the installation of full-time surveillance cameras, government officials said Friday.

The new policy, issued March 31 to security officers at the archives, lays out toughened steps for safeguarding research rooms used by nongovernmental employees who are given special access to classified material. And it demands “continuous monitoring” of anyone reviewing such material.

The restrictions were put in place as a direct result of the Berger episode, said a government official who spoke on condition of anonymity because of the sensitivity surrounding the continuing investigation. . . .

National Archives officials have reached no judgments on Mr. Berger’s motives in removing the documents, and one law enforcement official said, “We don’t know what he was thinking when he did it.”

Nonetheless, officials at the National Archives viewed the episode as troubling enough that they reviewed their security procedures and issued new guidelines for dealing with nongovernmental researchers like Mr. Berger.

Wouldn’t want any more of those inadvertent losses, I guess.