What is the test for claiming qualified immunity for civil damages against a police officer in a civil case?

Under title 42 of the United States Code section 1983, a plaintiff may allege a deprivation of a right secured by the Constitution of the United States or federal law, and that the "deprivation was committed by a person who was acting under color of state law."¹¹ (West v. Atkins (1988) 487 U.S. 42, 48.) At the same time, however, the decisional law recognizes a "qualified immunity" that protects against the concern that officers may be chilled in their daily pursuit of investigations and arrests. Otherwise, any person could bring an officer into a lawsuit to extract vengeance for arrest. This qualified immunity protects officers not only against trial and judgment, but also the chilling effect that would be caused by the expense of litigation. (Harlow v. Fitzgerald (1982) 457 U.S. 800, 816-819.)

"The doctrine of qualified immunity protects government officials 'from liability for civil damages insofar as their conduct does not violate clearly established statutory or constitutional rights of which a reasonable person would have known.' [Citation.] Qualified immunity balances two important intereststhe need to hold public officials accountable when they exercise power irresponsibly and the need to shield officials from harassment, distraction, and liability when they perform their duties reasonably." (Pearson v. Callahan (2009) 555 U.S. 223 [129 S.Ct. 808, 815, 172 L.Ed.2d 565].) "Because qualified immunity is 'an immunity from suit rather than a mere defense to liability... it is effectively lost if a case is erroneously permitted to go to trial." (Id. at p. 815.) Therefore, it is important to "'resolv[e] immunity questions at the earliest possible stage in litigation.'" (Ibid.)

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