In all criminal investigations and prosecutions, in all civil investigations and defendant based on a complaint that the defendant failed to perform a legal duty, resulting in harm to the plaintiff. Source: U.S. DOJ “>lawsuit. Participants (plaintiffs and defendants) in lawsuits are called litigants. Source: U.S. DOJ “>litigation (affirmative and defensive), and in all civil law enforcement investigations and proceedings, attorneys for the government shall conform their conduct and activities to the state rules and laws, and federal local court rules, governing attorneys in each State where such attorney engages in that attorney’s duties, to the same extent and in the same manner as other attorneys in that State, as these terms are defined in §77.2 of this part.