Replies

https://oig.justice.gov/reports/2016/1607.pdf - list of 10 jurisdictions (8 local; plus California/Connecticut)

https://oig.justice.gov/testimony/t160927.pdf - OIG report to Congress

https://www.justice.gov/opa/file/897651/download - another DOJ official makes a report

http://culberson.house.gov/uploadedfiles/2016-7-7_section_1373_-_doj_letter_to_culberson.pdf - Letter to this congressman on this topic

https://www.dhs.gov/xlibrary/assets/guidance-state-local-assistance-immigration-enforcement.pdf - DHS whitepaper

https://www.law.cornell.edu/uscode/text/8/1373 - the United States Code on this topic. For convenience, I’m including the text herein. Note that wherever you see “Immigration and Naturalization Service” (INS) that those functions are now performed by DHS-ICE as the federal government did some restructuring of departments/agencies to move all such functions over to ICE during the Bush43 administration.

8 U.S. Code § 1373 - Communication between government agencies and the Immigration and Naturalization Service

(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 entitiesNotwithstanding 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.