Qualified or "good faith" immunity is an affirmative defense against a lawsuit that must be asserted (pled) by a defendant government official. Gomez v. Toledo, 446 U.S. 635 (1980).
The U.S. Supreme Court established that the "good faith" defense has both an "objective" and a "subjective" aspect.
The objective element involves a presumptive knowledge of and respect for "basic, unquestioned constitutional rights." Wood v. Strickland, 420 U.S. 308, 322 (1975).
The subjective component refers to "permissible intentions." Id.
Typically the Supreme Court has defined these elements by identifying the circumstances in which qualified immunity would not be available. Referring both to the objective and subjective elements, it has held that qualified immunity would be defeated if an official "knew or reasonably should have known that the action he took within his sphere of official responsibility would violate the constitutional rights of the [plaintiff], or if he took the action with the malicious intention to cause a deprivation of constitutional rights or other injury ...." Id. (emphasis added).