We thought the security measures that were instituted after Sept. 11, 2001, would be it, and we all felt pretty safe again. Then came the anthrax attacks, and security was tightened further. One of the anthrax-laced letters was discovered Oct. 15, 2001, in Senate Majority Leader Tom Daschle’s suite in the Hart Senate Office Building. During the months that followed, Capitol Hill looked like a science fiction movie as workers in protective suits looked for signs of contamination, like this scene on Oct. 23, 2001.