CNN said a travel itinerary and boarding pass in the name of Michael V. Walter was found with the documents. Walter runs the DHS BioWatch Program. The program bills itself as "the nation's only system for early warning of an aerosolized biological attack and a cornerstone of the DHS comprehensive strategy for countering terrorism."
The documents, CNN said, included an analysis of the exercises, designed to evaluate the ability of local and federal public health and law enforcement to coordinate a response if a biological attack took place in Minneapolis on Super Bowl Sunday.
The exercises identified several issues, including a claim that some local officials "possess only a cursory knowledge of the BioWatch program and its mission," CNN said.
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CNN said it found the documents before Sunday's game, in which the Philadelphia Eagles defeated the New England Patriots. The documents were supposed to be locked up after business hours and shredded before being discarded, CNN said.
Homeland Security spokesman Tyler Q. Houlton downplayed the discovery of the documents. Houlton said DHS worked with federal, state and local officials for two years to prepare for the Super Bowl.
He said the drills were conducted to evaluate and improve coordination, communication and decision-making in the event of a national security threat.
"This exercise was a resounding success and was not conducted in response to any specific, credible threat of a bioterrorism attack," Houlton said in a statement.