Robert Ritter
In 1936 , Ritter was appointed head of the Racial Hygiene and Demographic Biology Research Unit of Nazi Germany's Criminal Police , to establish the genealogical histories of the German "Gypsies" , both Roma and Sinti , and became the "architect of the experiments Roma and Sinti were subjected to . " His pseudo-scientific "research" in classifying these populations of Germany aided the Nazi government in their systematic persecution toward a goal of "racial purity" . 
<triplet> Sinti <subj> Roma <obj> subclass of