Of course, the Soviets actually committed the Katyn Forest Massacre (mass murder of around 22,000 Poles in April and May 1940), although they did not admit it until 1990.
At Nuremberg, the Soviets also attempted to convict the Germans of mass extermination of Jews (and others) at the internment camps inside of Germany. Years later, even historians and Holohoax propagandists had to admit that no homicidal gassings or mass exterminations took place in the German camps located on German soil, and the story shifted to the German camps in Poland (which the Soviets controlled after the war, and where little to no investigation into the claims was allowed).
The following is an excerpt from "An Introduction to Holocaust Revisionism" by Tom Moran, an excellent article/primer, even for those not new to Holocaust™ revisionism.
Evil beyond contempt
The Katyn Forest is an area in Poland were the Soviets had massacred thousands of Polish cadre. When the Germans wrested control from the Soviets they were informed of thousands being driven out to the forest never to be seen again. The Germans located the mass graves and did a forensic archeological investigation.
At the Nuremberg trials where the Soviets sat as prosecutors and judges themselves they introduced the massacre as a German crime and the Allied members allowed it even though they knew who really did it, which tells us something ugly about the nature of the trials. Super exemplifying the basic mode of Holocaust evidence, the Soviets submitted a report hundreds of pages long totally founded on "eyewitness" accounts. The reality eventually surfaced in the form of an extant German report, complete with photographs of the excavation as it was happening along with foreign forensic experts and journalists invited and Allied POW officers brought in to witness the scene, all photographed at the scene.
With the advent of Glasnost the Soviets eventually came to admit to the crime.
The German report stands ironically and poetically as the only real documented forensic investigation ever performed on any mass grave stemming from the WW II era.
The incident of the Katyn Forest being introduced to the Nuremberg Tribunal stands as monolithic evidence that the trials were a farce. In addition to that one grand indictment the determinations of the Tribunal also included finding the defendants guilty of mass extermination at camps in Germany, since erased from the story, and the 4,000,000 number for Auschwitz currently 1,000,000. Inquiring minds have gone over the records of the trials and the case for a kangaroo court is outstanding.
Katyn, Russia, April 1943. The Germans discovered here the bodies of 4,500 Polish officers buried in mass graves. A Red Cross commission concluded that they had been killed by Soviet troops in the spring of 1940, when around 25,000 people disappeared.
According to the Soviet prosecutors, not only did the Germans carry out the Katyn Forest Massacre, but they then lied to the Poles by blaming it on the Soviets by finding "false witnesses", and even dug up the graves at Katyn Forest and brought additional dead bodies of Poles to Katyn Forest in order to increase the numbers of victims they could "frame" the Bolshevists for. Rich. Read it all in the official Nuremberg Trial Proceedings here:
source: Nuremberg Trial Proceedings Vol. 7, 59th Day, Thursday, 14 February 1946, Morning Session, pg 425-427 (Yale Law School)
I should now like to turn to the brutalities committed by the Hitlerites towards members of the Czechoslovakian, Polish, and Yugoslavian Armies. We find, in the Indictment, that one of the most important criminal acts for which the major war criminals are responsible was the mass execution of Polish prisoners of war, shot in the Katyn Forest near Smolensk by the German fascist invaders.
I submit to the Tribunal, as a proof of this crone, official documents of the special commission for the establishment and the investigation of the circumstances which attended the executions. The commission acted in accordance with a directive of the Extraordinary State Commission of the Soviet Union....
It would take too long to read into the record that precise and detailed document which I now submit to you as Exhibit Number USSR-54 (Document Number USSR-54), which is a result of the investigation. I shall read into the record only a few comparatively short excerpts. On Page 2 of the document, which is Page 223 in your document book, we read- this passage is marked in your file:
"According to the estimates of medico-legal experts, the total number of bodies amounts to over 11,000. The medico-legal experts carried out a thorough examination of the bodies exhumed, and of the documents and material evidence found on the bodies and in the graves. During the exhumation and examination of the corpses, the commission questioned many witnesses among the local inhabitants. Their testimony permitted the determination of the exact time and circumstances of the crimes committed by the German invaders."
...You will find the lines read into the record on Page 43 of Exhibit Number USSR-54 if you turn to the original document, or on Page 264 of your document book:
"General Conclusions: On perusal of all the material at the disposal of the special commission, that is, the depositions of over 100 witnesses questioned, the data of the medico-legal experts, the documents and material evidence and belongings taken from the graves in Katyn Forest, we can arrive at the following definite conclusions:
1. The Polish prisoners of war imprisoned in the three camps west of Smolenskand engaged in railway construction before the war, remained there after the occupation of Smolensk by the Germans, right up to September 1941.
2. In the autumn of 1941, in Katyn Forest, the German occupational authorities carried out mass shootings of the Polish prisoners of war from the above-mentioned camps.
3. Mass shootings of Polish prisoners of war in Katyn Forest were carried out by German military organizations disguised under the specific name, 'Staff537, Engineer Construction Battalion,' commanded by Oberleutnant Arnes and his colleagues, Oberleutnant Rex and Leutnant Hott.
4. In connection with the deterioration, for Germany, of the general military and political machinery at the beginning of 1943, the German occupational authorities, with a view to provoking incidents, undertook a whole series of measure to ascribe their own misdeeds to organizations of the Soviet authorities, in order to make mischief between the Russians and Poles.
5. For these purposes:
a. The German fascist invaders, by persuasion, attempts at bribery, threats, and by barbarous tortures, endeavored to find 'witnesses' among the Soviet citizens from whom they obtained false testimony, alleging that the Polish prisoners of war had been shot by organizations of the Soviet authorities in the spring of 1940.
b. The German occupational authorities, in the spring of 1943, brought from other places the bodies of Polish prisoners of war whom they had shot, and laid them in the turned up graves of Katyn Forest with the dual purpose of covering up the traces of their own atrocities and of increasing the numbers of 'victims of Bolshevist atrocities' in Katyn Forest.
c. While preparing their provocative measures, the German occupationalauthorities employed up to 500 Russian prisoners of war for the task of digging up the graves in Katyn Forest. Once the graves had been dug, the Russian prisoners of war were shot by the Germans in order to destroy thus all proof and material evidence on the matter.
6. The date of the legal and medical examination determined, without any shadow of doubt:
a. That the time of shooting was autumn 1941.
b. The application by the German executioners, when shooting Polish prisoners of war, of the identical method - a pistol shot in the nape of the neck -as used by them in mass murders of the Soviet citizens in other towns, especiallyin Orel, Voronetz, Krasnodar and in Smolensk itself."
THE PRESIDENT: The Tribunal will now recess.
via the research of Carlos Whitlock Porter