We often receive calls from people wondering what they can do after they've successfully defended a criminal prosecution. One claim people often want to discuss in that situation is defamation. Defamation is a type of civil wrong that encompasses verbal or written false statements. Successful criminal defendants frequently ask whether they can sue the prosecutor for alleged false statements made as part of the investigation and prosecution, including statements made in court. The answer is probably not.
The first hurdle that people often encounter in this situation is proving that the prosecutor made a false statement. Prosecutors' written and verbal statements often constitute either argument or a simple repetition of the facts of the case derived from a witness or a document. What we hear a lot is that people want to sue prosecutors for eliciting false testimony during a criminal trial. But how do you know that the testimony was false? And how do you know that the prosecutor knew that the testimony was false? Just because a criminal defendant wins or disagrees with a witness's testimony doesn't automatically make that testimony false, and certainly doesn't automatically lead to the conclusion that the prosecutor suborned perjury. Testimony often conflicts during a trial; a verdict for one party doesn't necessarily mean that the jury disbelieved the other party's witnesses. It might just mean that the jury found one side's evidence more credible or persuasive than the other.
Even if a criminal defendant could prove that a prosecutor made a knowingly false statement at some point, prosecutors enjoy two forms of immunity from defamation claims that make it very difficult to pursue such claims against a prosecutor. Prosecutors are entitled to absolute immunity for quasi-judicial activities, i.e., activities intimately associated with the judicial phase of the criminal process. The quasi-judicial activities to which absolute immunity attaches may occur inside or outside the courtroom. They include the initiation of a prosecution, the presentation of the state's case in court, or actions preparatory for these functions. Absolute immunity means that the prosecutor cannot be sued for defamation under any circumstances, even if a false statement was made knowingly and for an improper purpose.
Not all prosecutorial functions are entitled to absolute immunity. A prosecutor's administrative duties, investigatory functions, and advice to law enforcement that do not relate to preparation for the initiation of a prosecution or for judicial proceedings are not entitled to absolute immunity. Absolute immunity attaches to specific activities engaged in by a prosecutor. Absolute immunity does not exist merely by virtue of a civil defendant's status as a prosecutor. Instead, these types of prosecutorial activities are entitled to qualified immunity. Under a qualified immunity analysis, a prosecutor may escape liability for making a false statement if the prosecutor had a good faith belief that the statement was true.
Iowa's law of absolute immunity has protected prosecutors in some surprising situations. Prosecutors have been determined to be absolutely immune from liability in the following situations: Criminal charges used as leverage in settlement negotiations for a client in an associated civil matter; maliciously filing a complaint without probable cause; malicious institution of criminal proceedings against a man whose wife the prosecutor was representing in their divorce; and the decision whether to bring or not bring criminal charges, including whether to not bring criminal charges because of the law enforcement officer involved in the matter. But in other cases, prosecutorial activities have been determined to be entitled to only qualified immunity, such as: Writing a letter to law enforcement; holding a press conference; and personnel matters.