first preventers
n. The law enforcement or intelligence personnel who are in the most advantageous position to prevent a terrorist attack.
Other Forms
Since Sept. 11, 2001, the nation has heard a lot about local first responders, the law enforcement, health and safety workers who will be the first on the scene if terrorists hit near home again.

Thursday, California homeland security chief George Vinson introduced a new anti-terrorism phrase he says was coined by Gov. Gray Davis.

"First preventers" from all levels of California government, the military and federal intelligence agencies came together at the Lawrence Livermore Laboratory to link their resources, share expertise and talk about how to best protect the United States from another massive terrorist attack or disruption.
—Taunya English, “'First preventers' discuss security,” Contra Costa Times, April 18, 2003
2002 (earliest)
Sen. Joseph Lieberman said he was impressed with South Carolina's homeland defense program after a brief meeting with state officials and a tour of the emergency operations center here Monday.

Lieberman, the Senate Governmental Affairs Committee chairman, is helping create the proposed Department of Homeland Security. He said the visit gave him some good ideas on intelligence gathering and communication between different levels of emergency officials.

Democratic Gov. Jim Hodges signed a homeland security bill earlier this month that allows for more cooperation between state and federal agencies and more wiretapping capabilities for law enforcement.

"Not only are the first responders at the local level … but you might say the first preventers are at the local level as well," Lieberman said.
—Jacob Jordan, “Lieberman impressed with S.C's homeland defense program,” The Associated Press, July 15, 2002
As the first example citation makes clear, the term first preventers is based on the existing phrase first responders (1980), the first official personnel on the scene of an accident, attack, or disaster. Much of the discussion on the structure and funding of the Department of Homeland Security has focused on turning first responders into first preventers by giving them access to some of the resources normally available only to the security and intelligence communities. For example, by coordinating databases, local police would have the ability to run extensive background checks on suspicious individuals.

Note, too, that the first example citation credits California governor Gray Davis with coining first preventer, but I could find no evidence to support that claim. The first use (although not necessarily coinage credit) goes to senator Joseph Lieberman (see the earliest citation).