What is the scope of prosecutorial immunity in the criminal justice system?

While the prosecutorial immunity is frequently called "absolute", it is clear that this term cannot be taken literally. The purpose of the immunity is to enable prosecutors to "exercise a discretionary judgment on the basis of evidence presented to them," in a "vigorous and fearless" manner, without fear of civil liability as a result. Imbler v. Pachtman, 424 U.S. 409, 422-423, 426-427, 96 S.Ct. 984, 991 at note 20, 993, 47 L.Ed.2d 128. And an analysis of the immunity decisions shows that its scope is limited by its purpose that is, to prosecutorial acts that entail evaluation of evidence.