Domestic Defense Fund Act of 2004

Domestic Defense Fund Act of 2004 - Authorizes the Secretary of Homeland Security to award grants to States, units of local government, and Indian tribes for homeland security development. Requires grant awardees, among other requirements, to develop a homeland security plan identifying both short- and long-term homeland security needs. Provides authorized uses of grant assistance, including: (1) funding additional law enforcement, fire, and other emergency response resources and equipment; and (2) improving cyber and infrastructure security. Requires one percent of grant funds to be reserved for Indian tribes. Requires 70 percent of grant funds to be allocated among metropolitan cities and urban counties based on the Secretary's calculations of various infrastructure vulnerabilities and threats such as proximity to international borders, nuclear or other energy facilities, air, rail or water transportation, and national icons and Federal buildings. Requires the remaining percentage to be allocated among the States for use in non-qualifying communities (not a metropolitan city, urban county, or Indian tribe).

Requires certifications and annual reports with respect to grant uses. Provides for grant reallocations for failure to comply with use requirements.

Allocates funds to States, regional cooperations, and units of local government for: (1) homeland defense planning; (2) increased security through additional first responder personnel; (3) purchasing and refurbishing protective equipment for such personnel; (4) the development and maintenance of Statewide training facilities and homeland security best practices clearinghouses; and (5) the development and maintenance of communications systems that can be used between and among first responders, including law enforcement, fire, and emergency medical personnel.

Allocates funds for discretionary grants to high-threat, high-density urban areas, and for the protection of critical infrastructure.

Earmarks funds for a flexible emergency assistance fund for States and local governmental units that incur extraordinary homeland security costs.

Directs the Department of Homeland Security to develop national homeland security preparedness, first responder training, and equipment standards, and best practices for the use of funds authorized and allocated under this Act.

Mandates a ten percent matching funds requirement from grant recipients.