With the coming into power of the National-Socialists, this policy was continued in an aggravated manner. The Information Bureau in Munich was renamed in 1938 to become the “Reich Criminal Office for the Fight against the Gypsy Menace” and integrated into the central criminal office of the Reich in Berlin. Parallel to the registration by the police, the central criminal office selected scientists to assign them to the systematic registration of the entire population of Roma and Sinti in Germany. For these purposes, the so-called “Racial-hygienic Research Center” was founded at the central health department. It was headed by the physician Dr. Robert Ritter, the funding for the “research work” was provided by the German Research Group.

Ritter considered the Roma to be a “criminal and anti-social race” which had to be eliminated. He called his field of research “criminal biology” and presumed that the Roma and Sinti as a people had criminal tendencies which were inherited genetically. In the first phase of his work, Ritter differentiated between “purebred gypsies” and “half-breed gypsies”, whom he considered to be especially “anti-social”. In one of his work reports, he wrote:

“The Gypsy question can only be considered as solved when the majority of the anti-social and useless half-breed gypsies has been deported to big work camps and the reproduction of this half-breed population has thus been put to an end. Only then will the future generations of the German people be rid of this burden.”

Ritter’s “Research Center” employed a number of scientists, among them the anthropologists Dr. Eva Justin, Professor Sophie Erhardt as well as Dr. Ruth Kellermann from Hamburg. They were assigned to compile family genealogies by which the “degree of crossbreeding” of Roma and Sinti could be assessed. The archive that Ritter and his employees created was then forwarded to the police and was used to arrest the recorded families and deport them to concentration camps. Only a few returned from these camps. In the gas chambers of the concentration camps alone, half a million Roma and Sinti were killed. In the countries of Eastern Europe, another hundreds of thousands of Roma fell victim to the execution commands of the German occupiers during the Second World War. The exact number of victims is unknown to this date.