U.S. Code Title 8 - Aliens and Nationality
U.S. Code Title 8 - Aliens and Nationality says the following:
Chapter 12 - Immigration and Nationality
Subchapter II - Immigration
(a) In general Notwithstanding any other provision of Federal, State, or local law, a Federal, State, or local government entity or official may not prohibit, or in any way restrict, any government entity or official from sending to, or receiving from, the Immigration and Naturalization Service information regarding the citizenship or immigration status, lawful or unlawful, of any individual.
(b) Additional authority of government entities Notwithstanding any other provision of Federal, State, or local law, no person or agency may prohibit, or in any way restrict, a Federal, State, or local government entity from doing any of the following with respect to information regarding the immigration status, lawful or unlawful, of any individual:
(1) Sending such information to, or requesting or receiving such information from, the Immigration and Naturalization Service.
(2) Maintaining such information.
(3) Exchanging such information with any other Federal, State, or local government entity.
(c) Obligation to respond to inquiries
The Immigration and Naturalization Service shall respond to an inquiry by a Federal, State, or local government agency, seeking to verify or ascertain the citizenship or immigration status of any individual within the jurisdiction of the agency for any purpose authorized by law, by providing the requested verification or status information.
(Pub. L. 104-208, div. C, title VI, Sec. 642, Sept. 30, 1996,110 Stat. 3009-707.)
Section was enacted as part of the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, and also as part of the Omnibus Consolidated Appropriations Act, 1997, and not as part of the Immigration and Nationality Act which comprises this chapter.
U.S. Code Title 8 Section 1324a
Section 1324c states, "All officers whose duty it is to enforce criminal laws shall have authority to make arrests for a violation of any provision of this section" (affirmed U.S. v. Perez-Gonzalez 2002 Fed App 0360, 6th Circ.).
Section 1644, same title states, "No local ordinance, rule, or measure shall stop law enforcement officers from enforcement of this section" (affirmed Southern District Court of NY, U.S. v. Rudy Guiliani,1996).