Kangaroo court is an informal pejorative term for a court that ignores recognized standards of law or justice, carries little or no official standing in the territory within which it resides, and is typically convened ad hoc.[1] A kangaroo court may ignore due process and come to a predetermined conclusion. The term is also used for a court held by a legitimate judicial authority, but which intentionally disregards the court’s legal or ethical obligations (compare show trial).[2]
https://en.wikipedia.org/wiki/Kangaroo_court
A show trial is a public trial in which the guilt or innocence of the defendant has already been determined. The purpose of holding a show trial is to present both accusation and verdict to the public, serving as an example and a warning to other would-be dissidents or transgressors.[2]
Show trials tend to be retributive rather than corrective, and they are also conducted for propagandistic purposes.[3] When aimed at individuals on the basis of protected classes or characteristics, show trials are examples of political persecution. The term was first recorded in 1928.[4]