Leuchter Report

The Leutcher Report is the name by which an expert investigation conducted in 1988 by the American Frederick A. (Fred) Leuchter, Jr., a specialist in the design and construction of equipment for execution in the prisons of the United States, is known. This report was created for the purpose of defending Ernst Zündel , prosecuted for denial of the Holocaust .

For this, the report who was supposed to be a specialist in gas chambers put into question the existence of gas chambers at Auschwitz I, Auschwitz-Birkenau and Majdanek . The alleged expert report was dismissed by the court as evidence of Leuchter’s lack of professional competence to carry out the expert’s report and was also scientifically discredited during the trial for the lack of rigor in collecting the samples and in their analysis and interpretation of their Results. Similarly, during his statement before the judge, Leuchter was obliged to recognize from the inaccuracy to the complete falsity of numerous statements contained in the report. Despite all of this, it is still used by supporters of Holocaust denialism as one of the most important evidence to back up its claims.


The famous denialist Ernst Zündel hired Leuchter in 1988 to conduct an expert’s report on the gas chambers at Auschwitz, Birkenau and Majdanek, in order to use the report in his favor in one of the trials to which he was subjected over the years 1980 for the charge of fomenting racial hatred through the publication of negationist pamphlets. Leuchter accepted the commission in exchange for $ 35,000 and after a meeting where he reviewed photographs of concentration camps during the war, plans for crematoriums and gas chambers, documents on Zyklon B and slides taken from sites by the investigator Swedish Ditlieb Felderer in 1970.

On February 25, 1988, Fred A. Leuchter traveled to Poland along with his wife Carolyn, cameraman Jürgen Neumann, cartoonist Howard Miller and the collaboration of the Polish interpreter Tjudar (Theodor) Rudolf. Using a hammer and a chisel, they extracted without permission from the chambers of extermination and of disinsecting pieces of walls and of the floor of diverse thickness. They returned on March 3, after eight days of stay in Poland to analyze the samples obtained. The samples were given to the laboratory led by the American chemist James Roth , without being informed of where they came from, only that it was an expert analysis for a trial.

The chemical report from Roth’s laboratory found that the samples of mortar allegedly extracted from the disinfection chambers contained a high cyanide content and that, on the other hand, those extracted from the extermination chamber contained a zero or negligible trace. Based on these results, Leuchter wrote a 192-page report in which, through misguided scientific reasoning, he concluded that there would be no gas chambers for executions in any of the three camps and that the gas chambers found there could not have been Never functioned to execute executions, but could only have served for the fumigation of parasites. That report was then intended to be scientifically proved that there were no extermination chambers.

However, subsequently, in an interview, Dr. Roth indicated that cyanide would have formed an extremely thin layer on the walls, a thickness of one-tenth of a human hair [ citation needed ] . Leuchter had taken samples of indeterminate thickness. Not informed of this, Roth had pulverized the whole samples, seriously diluting the cyanide layer containing each sample with an undetermined amount of brick, varying for each sample. To explain the inadequacy of the procedure, Roth offers the analogy that the results would be like to analyze the wood of a wall when what one wants to know is the composition of the painting.

Although Leuchter was admitted to testify at the Zündel trial, the report was finally rejected by the court because of the author’s lack of professional credentials. In October 1990, a Massachusetts court criminally prosecuted Leuchter for practicing as an engineer without a license. It was learned that not only did not have a license, but had no degree or study related to engineering or any other professional accreditation apart from a BA in History, which ended in 1964. Admitted to the court not having any training or experience in Toxicology , Biology or Chemistry. It was also discovered that although he had some experience in electric chairs and lethal injections, he had no knowledge of gas chambers, contrary to what he had stated before.

In spite of being totally discredited, the report was widely disseminated among the deniers, who believed that it had the definitive support of their beliefs. Scientists and forensic experts, however, claimed the impossibility of detecting cyanide fifty years later with their method (the analyzes that were done at the end of the war on the ventilation ducts of the disinfection chambers showed significant amounts of cyanide), on samples Obtained from chambers that had been demolished by the Nazis and partially rebuilt by the Soviets. Leuchter was unaware of which part had been rebuilt, so he could not prove whether the samples corresponded to original material from the gas chambers.

Exposed Arguments and Refutation

Leuchter’s argument was based on the following points, all radically false from the scientific and historical point of view:

The chemical analysis

The results of the chemical analysis performed by Dr. Roth determined that:

  • The samples taken from the disinfection chambers (many of them preserved intact until today) contained a very high amount of cyanide and in most of them residues of Prussian blue were found on its surface.
  • The samples extracted from the extermination chambers (in ruins and in the open since their destruction at various moments of World War II) contained a zero or minimal trace of cyanide, all of them lacking such prussian blue residues on their surface .

From these results, Leuchter concludes that since in the remains of the homicidal chambers the concentration of residues detected is lower than in the desparasite, this would prove that in the former the large-scale gassings were not carried out. History gives for certain. However, the conclusion can not necessarily be deduced from the analysis of the results, so the conclusion is invalid.

The premise that led to Leuchter to request chemical analysis of traces of cyanide deposited materials chambers was the assumption that they necessarily would last until today and would be a reliable indicator of the intensity of use of gas. This assumption is based on the fact that one of the possible compounds formed by the deposition of Zyklon B (or more precisely, of its active ingredient HCN ) is Prussian Blue , a highly persistent and poorly soluble in water. Thus, for Leuchtner, the presence of smaller amounts of cyanide residues and the complete absence of Prussian blue in the debris of the extermination chambers would prove that they did not make a large-scale homicidal use of Zyklon B. This hypothesis is Erroneous, because it ignores several key points regarding the behavior of possible residues:

– Other compounds of cyanide possibly deposited in their day are highly soluble and could not withstand an exposure of more than 40 years to the elements, falsifying quantitatively the result obtained today.

– The formation of Prussian Blue – the most persistent residue – requires conditions of temperature, PH , surface nature and, above all, time and initial concentration of HCN which, precisely because of the way of operation described by the witnesses, could hardly In the extermination chambers, but they are possible in the disinfection chambers. Thus, the existence of Prussian blue could be considered a test of gassing, but its absence is not proof that they were not produced.

– The concentration and exposure time required to kill a human with Zyklon B (about 300 ppm and 20 minutes) are much lower than those required to kill insects in the disinfection chambers (depending on the species, up to 10,000 or more Ppm and 12, 24 or more hours): finding less waste in the extermination chambers than in the disinfection chambers was a predictable result. Leuchter acknowledged before the court that he formulated the conclusions of his report ignoring these data and thinking that it happened in reverse and that humans were more resistant to gas than insects.

In addition, chemical analysis similar to that of Leuchter had already been performed twice, the first by the Institute of Forensic Medicine in Krakow , at the express request of the Auschwitz Museum, and the second by the German chemist Germar Rudolf . Rudolf came to the same conclusions as Dr. Roth’s analysis, which he criticized in some minor points. The results obtained by the Institute of Forensic Medicine in Krakow found in the samples of the extermination chambers, traces of cyanide even weaker than those found by Dr. Roth

Other points treated in the report

  • The doors are not hermetically sealed, that is to say, that there have been continual leaks of lethal gas. When performing an execution, the gas had entered the hospital of the SS that was in front and would have killed doctors and patients.

The doors were sealed, by thick strips of felt fixed to the frames, which ran all around the perimeter of the cracks in the doors. Remains of such felt can be seen on the doors of existing disinfection chambers. Although it may surprise the use of such a crude system, it was actually more elaborate than the usual sealing procedure in civilian employment as Zyklon B pesticides and other brands of cyanide compounds similar to it, in which door and window joints Of the fumigated premises were sealed by introducing old rags or damp newspaper. At the end of the gassing, the gas was discharged directly into the atmosphere, just as in civilian employment, spreading so rapidly that it would make virtually impossible the contamination of any nearby building.

  • Gas distribution mechanisms and heating systems are lacking, since in order for the Zyklon B to volatilize within half an hour, the disinfection chambers need to be heated to at least 25 ° C.

The extermination chambers had a complete system of ducts and fans for the extraction and extraction of air. The plans used in its construction, technical specifications and orders to supplying companies are preserved in the museum of Auschwitz. It is false that a heating system is required: 25 ° C is the boiling point of the HCN contained in Zyklon B, but it is not necessary for the temperature to be reached so that the venom diffuses: given its very high vapor pressure , it is Fully effective at lower and even near zero ambient temperatures, as outlined in reports from field experiments conducted by the manufacturers themselves.

  • Not enough ventilation. When an execution was carried out, it would not have been possible to effectively ventilate a chamber to perform another execution, as the witnesses say.

Witnesses do not assert that executions took place instantly, but unanimously agreed that since the door was closed and the gas was being discharged, the gassing lasted for about 20-30 minutes, and then approximately another was expected for the renewal of air. Once the doors had been opened, the bodies had to be dislodged and the remains of vomiting, blood, etc., which had been left over, had to be cleaned with water hoses, all of which took time.

  • The Zyklon B can remain even a week after a single gas, in quantity necessary to signify a danger to anyone who had access to the camera.

With the ventilation system installed, the extermination chambers completely renewed their air in less than an hour. Before that time, the interim concentration would go down to non-lethal levels that would open doors and even access the interior. If it were necessary to enter the chamber immediately after the gassing, the personnel in charge could be equipped with the standard German gas mask, for which there were suitable filters fully effective against the Zyklon B.

  • The chambers are each built in the same building where the crematoria are, with Zyklon B gas being an explosive gas.

Zyklon B is explosive only at concentrations above 56,000 ppm . 300 ppm are lethal to humans in about 20 minutes. There is therefore a huge margin of safety before an accidental explosion could occur.

  • The doors of all the gas chambers open inwards, so the sonderkommando or special commanders could not have entered the chamber full of corpses to extract them.

There are still many doors analogous to those of the extermination chambers at Auschwitz, where it can be seen that they opened to and from outside, with handles and hinges outside the room. Yes it is true that there were disinfection chambers of clothes with opening inwards.