A U.S. Supreme Court case earlier this year, Rehberg v. Paulk, extended the immunity given to witnesses against liability for testimony given at trial to witnesses testifying before a grand jury. Rehberg v. Paulk additionally held that there is no difference between a law enforcement officer and a civilian witness for purposes of this immunity. In practice this means that an individual cannot sue a law enforcement officer for their grand jury testimony even if the officer lied or the testimony was malicious.
Rehberg v. Paulk involved a 42 U.S.C.§ 1983 action against a district attorney's chief investigator. The investigator testified before a grand jury in three separate indictments against the petitioner, all of which were subsequently dismissed due to insufficient evidence. The petitioner then filed a § 1983 claim charging the investigator with presenting false testimony to a grand jury and conspiracy to present false testimony to a grand jury.
42 U.S.C.§ 1983 actions entail violations of an individual's constitutional rights, immunities, and privileges by persons acting "under color of state law." §1983 allows an individual to sue any government official who uses his or her position to deprive that individual of constitutional or legal rights. However, certain government officials are immune from §1983 actions when performing duties within the scope of their authority.
The U.S. Supreme Court has long recognized that some functions carried out by government officials require absolute immunity from the threat of civil liability to ensure that those functions and duties are performed independently and objectively. The Court has recognized this absolute immunity for actions by government officials within the scope of their authority, including legislators, judges, prosecutors, and witnesses testifying at trial.
Witnesses testifying at a trial have long enjoyed absolute immunity from slander, libel and any other claims based on their testimony, even when their testimony was malicious and/or false. The Court reasoned that without this absolute immunity, witnesses would not be inclined to tell the truth for fear of subsequent civil claims against them. The Court also reasoned that this immunity would not make witnesses more likely to lie while on the witness stand because the possibility of criminal perjury charges acts as a significant deterrent.
In extending this immunity to grand jury witnesses, the Court stated that the same factors that justify immunity for trial witnesses apply to grand jury witnesses. Moreover, allowing § 1983 actions against grand jury witnesses would compromise the secrecy of grand jury proceedings, which is vital to their proper functioning.
The Court also held that there was no reason to distinguish law enforcement witnesses from lay witnesses, because if anything, the court reasoned that law enforcement officials face more severe sanctions for perjury than do lay witnesses. Sanctions can include the loss of employment and other employment -related penalties. Additionally, since prosecutors are immune from §1983 actions, it would be inconsistent to allow suits against law enforcement grand jury witnesses for malicious prosecution, because it is the prosecutor and not the officer who makes the decision on whether or not to prosecute.
In the end, the Court held that the absolute immunity granted to trial witnesses extends to grand jury witnesses, even if the grand jury witness is a law enforcement officer, and even if the officer lied under oath.