Adds new subsections (b) and (c) to 42 U.S.C. 1983 establishing qualified-immunity rules that limit immunity defenses for officers or agents of U.S. Immigration and Customs Enforcement and U.S. Customs and Border Protection engaged in law enforcement: (b)(1) bars any immunity defense where the plaintiff's alleged facts would constitute Fourth Amendment excessive force; (b)(2) permits immunity in other cases only if the defendant's conduct was consistent with rights clearly established at the time; and (c) requires courts to determine whether the alleged facts constitute a constitutional violation before addressing whether the right was clearly established.