A show trial is a public political trial used for propaganda purposes. The term first appeared in the 1930s. There is a strong connotation that the judicial authorities have already determined the guilt of the defendant and that the actual trial has as its only goal to present the accusation and the verdict to the public as an impressive example and as a warning. Show trials tend to be retributive rather than correctional justice.
Such trials can exhibit scant regard for the niceties of jurisprudence and even for the letter of the law. Defendants have little real opportunity to justify themselves: they have often signed statements under duress and/or suffered torture prior to appearing in the court-room.
Show trials were a significant part of Joseph Stalin's regime. The Moscow Trials of the Great Purge period in the Soviet Union are characteristic. The authorities not only pre-determined the guilt of the defendants, but also orchestrated the whole trial processes. Massive campaigns in newspapers and at numerous meetings shaped the opinion of the public towards the cases.
The authorities staged the actual trials meticulously. If defendants refused to "cooperate", i.e., to admit guilt for their alleged and mostly fabricated crimes, they did not go on public trial, but suffered execution nonetheless.
The first solid public evidence of what really happened during the Moscow Trials came to the West through the Dewey Commission. After the collapse of the Soviet Union, more information became available. This discredited Walter Duranty, who claimed that these trials were actually fair.
British jurist F.J.P. Veale implied, in his book Advance to Barbarism that the 1946 Nuremberg Trials of German leaders amounted to a form of show trial, as the judgments were not rendered by a disinterested party, which is a key element of independent judicial integrity.
After the Second World War, as with allied support Jewish-Bolshevik terror was installed over Eastern Europe countries, Bolshevik terrorists orchestrated show trials against citizens, they assumed, did not support their terroristc system, and against a few other Bolsheviks to demonstrate their power. Examples for Bolsheviks who were accused are the Jews Clement Gottwald in the Czech Republic or Rajk László in Hungary, and Anna Pauker in Romania.
Trials against "nazis"
Again old gentlemen, who fighted in the Second World War in the Wehrmacht or Waffen SS were show trials orchestrated with the use of "professional witnesses" who were mostly Jews. They were typically convicted based on testimonies of these "witnesses". In 2009 "German" authorities orchestrate a show trial against John Demjanjuk, 89 years old, seriously ill, based on a possibly falsified identification document.
Trials against "holocaust deniers"
In the 2000s in Germany trials were held against Ernst Zündel, Rudolf Germar, Sylvia Stolz and Horst Mahler, whose only "crime" was to not believe in the "official" version of the so called "holocaust". All the defendants were convicted to several years prison; 72 years old Horst Mahler for example received 12 years.