Whether § 1983 permits a damages action against a police officer for allegedly perjured testimony at a state criminal trial.
Holding
No. A police officer is absolutely immune from § 1983 damages liability for testimony given as a witness at a criminal trial.
Reasoning
Section 1983 must be read against the common-law immunities that Congress was presumed to know when it enacted the Civil Rights Act of 1871. Although the statute literally applies to every person acting under color of state law, the Court's precedents hold that Congress did not silently abolish longstanding common-law immunities. Judges are absolutely immune for judicial acts, and prosecutors are absolutely immune for their advocacy in initiating and pursuing prosecutions.
At common law, witnesses enjoyed an absolute privilege against later civil damages suits based on their testimony in judicial proceedings. That protection generally applied even when the witness was alleged to have testified falsely or maliciously, provided the testimony was relevant to the proceeding. The historical rule reflected a deeply rooted judgment that the individual interest in damages must sometimes yield to the need for an uninhibited judicial truth-seeking process.
Witness immunity protects the trial process by reducing the risk that prospective witnesses will refuse to testify or will alter their testimony out of fear of retaliatory litigation. A witness concerned about a later suit might shade testimony in favor of a potential plaintiff, emphasize uncertainty, or withhold details. The adversary process—oath, cross-examination, impeachment, and the factfinder's assessment of competing evidence—is the principal means by which courts test a witness's credibility.
A police officer who takes the stand performs the same witness function as any other witness: the officer testifies under oath, responds to direct and cross-examination, and remains subject to criminal prosecution for perjury. Immunity turns on the function being performed, rather than the witness's governmental status. Thus, an officer serving as a trial witness falls within the same traditional immunity that protects other participants whose roles are integral to a judicial proceeding.
The Court limited its ruling to trial testimony. It expressly did not decide whether LaHue would be immune for allegedly false testimony at probable-cause hearings, because the petition and briefing did not squarely present that question.