On July 8, 2010, FKSA filed an amicus curiae brief in United States v. Arizona on behalf of the firm's pro bono client, the Center on the Administration of Criminal Law ("CACL"), which is based at New York University School of Law. The U.S. government has sued the State of Arizona to declare invalid and enjoin the enforcement of Arizona Senate Bill 1070, as amended by Arizona House Bill 2162, which is intended "to discourage and deter the unlawful entry and presence of aliens" by making "attrition through enforcement the public policy of all state and local government agencies in Arizona." The U.S. government's complaint alleges that the Arizona statute is preempted by federal immigration law and therefore violates the Supremacy Clause of the U.S. Constitution and also violates the Commerce Clause. FKSA's brief, filed in support of the U.S. government's motion for a preliminary injunction, argues that the Arizona statute threatens public safety by undermining law enforcement efforts to maintain positive relationships and open lines of communication with the communities they serve.

FKSA attorneys Ricardo Solano Jr., Jessica A. Murzyn, Ellen London, and Christopher M. Colorado authored the brief with co-counsel Anthony S. Barkow and Anne Milgram of CACL.