How has the doctrine of qualified immunity been interpreted in the context of civil litigation?

The doctrine of qualified immunity shields police officers acting in their official capacity from suits for damages under 42 U.S.C. 1983, unless their actions violate clearly-established rights of which an objectively reasonable official would have known. See Harlow v. Fitzgerald, 457 U.S. 800, 818, 102 S.Ct. 2727, 73 L.Ed.2d 396 (1982); Ricciuti v. N.Y.C. Transit Authority, 124 F.3d 123, 127 (2d Cir.1997). This policy is justified in part by the risk that the "fear of personal monetary liability and harassing litigation will unduly inhibit officials in the discharge of their duties." Anderson v. Creighton, 483 U.S. 635, 638, 107 S.Ct. 3034, 97 L.Ed.2d 523 (1987).