Qualified Immunity Civil Rights

Saucier v. Katz held that qualified immunity in excessive force cases is not identical to the Fourth Amendment reasonableness inquiry. Courts must separately consider whether the alleged facts show a constitutional violation and whether that right was clearly established in the specific circumstances.

Pearson v. Callahan changed qualified immunity procedure. The Court held that judges are no longer required to decide the constitutional violation question before asking whether the law was clearly established.

Monell v. Department of Social Services of the City of New York: in Monell, the Supreme Court overruled part of Monroe v. Pape and held that local governments are 'persons' under § 1983. Municipalities may be liable when official policy or custom causes a constitutional violation, but not simply because they employ the person who committed the violation.

Harlow v. Fitzgerald, 457 U.S. 800 (1982), created the modern objective qualified immunity test: federal officials performing discretionary duties are protected from damages unless they violate clearly established rights a reasonable official would have known.

City of Canton v. Harris held that a municipality can be liable under § 1983 for failure to train police employees, but only when the failure reflects deliberate indifference to constitutional rights and causes the injury. The case is a foundation of modern Monell municipal-liability doctrine.