Persecution of Roma (Gypsies) in Germany, and indeed in all of Europe, preceded the Nazi takeover of power in 1933. The police in Bavaria, Germany, maintained a central registry of Roma as early as 1899, and later established a commission to coordinate police action against Roma in Munich. In 1933, police in Germany began more rigorous enforcement of pre-Nazi legislation against those who followed a lifestyle labeled "Gypsy." The Nazis judged such people to be racially "undesirable" and enacted systematic measures of persecution against the Roma.
After the Nazis had decided that Roma had alien blood, one of their main concerns was the systematic identification of all Romani people. A definition of "Roma" was essential in order to undertake systematic persecution. Classifying who was Jewish was in this sense easier because records held by religious communities were readily available to the state. Roma in Germany had been Christian for centuries, so ecclesiastical records were useless in determining Romani descent.
The Nazis turned to racial hygiene and sought to determine who was Romani based on physical characteristics. Dr. Robert Ritter, a child psychologist at the University of Tuebingen, became the central figure in the study of Roma. His specialty was criminal biology; that is, the idea that criminal behavior is genetically determined. In 1936, Ritter became the director of the Center for Research on Racial Hygiene and Demographic Biology in the Ministry of Health and began a racial study of Roma. Ritter undertook to locate and classify by racial type the estimated 30,000 Roma living in Germany. Ritter performed medical and anthropological examinations in an attempt to classify Roma. Despite Ritter's own claims to document his decisions with pseudo-science, his teams resorted to interviewing Roma to determine and record their genealogy. Ritter's interviewers threatened their subjects with arrest and incarceration in concentration camps unless they identified their relatives and their last known residence. In this way, Ritter established a register of almost all Roma then living in Germany.
At the conclusion of his study, Ritter declared that Roma, having originated in India, were once Aryan but had been corrupted by mingling with lesser peoples during their long migration. Ritter estimated that some 90 percent of all Roma in Germany were of mixed blood and were consequently carriers of "degenerate" blood and criminal characteristics. Because they allegedly constituted a danger, Ritter recommended they be forcibly sterilized. The remaining pure-blooded Roma, Ritter argued, were to be placed on a reservation and studied further. In practice, little distinction was made between Ritter's so-called pure-blooded and mixed-blooded Roma. They all became subject to the Nazi policy of persecution and, later, mass murder.
In 1936, the Nazis centralized all police power in Germany under Heinrich Himmler, SS chief and chief of the German police. Consequently, police policy toward Roma was also centralized. In Berlin, Himmler established the Reich Central Office for the Suppression of the Gypsy Nuisance. This agency took over and extended bureaucratic measures to systematically persecute Roma.
One of the agency's first decisions was to subject Roma to race laws. After 1936, Roma became subject to the Nuremberg Laws, the Law for the Prevention of Hereditarily Diseased Progeny, and the Law against Dangerous Habitual Criminals. Many Roma who came to the attention of the state were required to be sterilized.
Shortly before the opening of the 1936 Olympic Games in Berlin, the police ordered the arrest and forcible relocation of all Roma in Greater Berlin to Marzahn, an open field located near a cemetery and sewage dump in eastern Berlin. Police surrounded all Romani encampments and transported the inhabitants and their wagons to Marzahn. The arrests began at 4 a.m. on July 16, 1936. Uniformed police guarded the camp, restricting free movement into and out of the camp. Many of the 600 Roma arrested continued going to work every day, but were required to return each night. Later, they had to do forced labor in armaments plants.
All over Germany, both local citizens and local police detachments began forcing Roma into municipal camps. Later, these camps evolved into forced-labor camps for Roma. Marzahn and the Gypsy camps (Zigeunerlager) set up by the Nazis in other cities between 1935 and 1938 were a preliminary stage on the road to genocide. The men from Marzahn, for example, were sent to Sachsenhausen in 1938 and their families were deported to Auschwitz in 1943.
Romani individuals were also arrested as "asocials" or "habitual criminals" and sent to concentration camps. Nearly every concentration camp in Germany had Romani prisoners. In the camps, all prisoners wore markings of various shapes and colors, which identified them by category of prisoner. Roma wore black triangular patches, the symbol for "asocials," or green ones, the symbol for "professional" criminals.