SNIPER Act of 2003

So No Innocent Person Ever Repeats the Sniper Tragedy Act of 2003 (SNIPER Act of 2003) - Amends the Brady Handgun Violence Prevention Act to: (1) authorize the Secretary of the Treasury to inspect the inventory and records of a licensed importer, manufacturer, or dealer without reasonable cause or warrant not more than four times (currently, once) during any 12-month period; and (2) require such persons to maintain records of disposition of ammunition, except on .22 caliber rimfire ammunition.

Provides for enhanced penalties for violations. Subjects violators to revocation or suspension of any applicable license or a fine. Directs the Attorney General to send warning letters to alleged violators, issue notices of revocation, suspension, or imposition of a civil fine, and conduct proceedings, as appropriate.

Repeals an exemption from Brady Act requirements involving gun sales to instate residents.

Technological Resource to Assist Criminal Enforcement Act (TRACE Act) - Amends the Brady Act to require a licensed manufacturer or importer to: (1) test fire firearms manufactured or imported by certain licensees; (2) prepare ballistics images of the fired bullet and cartridge casings; (3) make the records available to the Attorney General for entry into an electronic database (established by this Act); and (4) store the fired bullet and cartridge casings as specified.

Directs the Attorney General to: (1) conduct mandatory ballistics testing of all firearms in the custody of Federal agencies; and (2) establish, within each Bureau of Alcohol, Tobacco, Firearms, and Explosives field division, a gun crime task force.