1219. 3 . Notably, qualified immunity and fair warning derive from two entirely separate sources. The fair warning requirement, which springs from the Due Process Clause, protects a defendant from criminal liability. See Harriss, 347 U.S. at 617, 74 S.Ct. 808. Qualified immunity, on the other hand, is a common-law "immunity from suit rather than a mere defense to liability,” Mitchell, 472 U.S. at 526, 105 S.Ct. 2806, which public officials typically invoke as a defense to 42 U.S.C. § 1983 claims. See, e.g., Pierson v. Ray, 386 U.S. 547, 554, 87 S.Ct. 1213, 18 L.Ed.2d 288 (1967) (applying qualified immunity to a police officer after noting that Congress never meant to abolish common-law immunities). 4 . Kastigarv. United States, 406 U.S. 441, 460-62, 92 S.Ct. 1653, 32 L.Ed.2d 212 (1972) (<HOLDING>). 5 . To justify dismissing an action for
holding that a defendant need only show that he testified under a grant of immunity in order to shift to the government the heavy burden of proving that all evidence it proposes to use was derived from legitimate independent sources holding that the government bears the burden of proving voluntary consent under the totality of the circumstances holding that the burden of proving that the employee did not make reasonable efforts is on the defendant holding that the government must satisfy its burden of proving contract damages holding that the moving party bears a heavy burden of proving the facts required for disqualification