Richter, Dieter Max

AUSTRIAN
FORENSIC SCIENTIST

In 1900, Dieter Max Richter made two important contributions to the world of forensic science. First, he adapted the Austrian Nobel Prize winning immunologist Karl Landsteiner's (1868–1943) technique for blood group typing for use on bloodstains. His second major contribution to the world of forensic science was his application of the scientific method; it was the first time that performance validation experiments were used to adapt a technique specifically for use within the field of forensic science.

With Landsteiner, Richter studied the agglutination of blood that occurs when one person's blood is brought into contact with that of another. They found that the blood of a person with type A would be agglutinated by anti-A serum; the blood of a person with type B would be agglutinated by anti-B serum; and the blood of an individual with type O blood would not be agglutinated by either anti-A serum or anti-B serum. Eventually, it was learned that blood types follow predictable distribution patterns: O is most common among indigenous peoples and Latin Americans; type A is most prevalent among Europeans and Caucasians; and B is most common among African Americans and some Asians.

When the pair had firmly established their methodology for typing and grouping human blood, they began to work with blood serum and other bodily fluids such as saliva, semen, and vaginal secretions, and were able to replicate their earlier work. They found the blood serum of some people could agglutinate the blood of others. From his earlier work, Landsteiner had devised the idea of three mutually incompatible blood groups, and labeled them A, B, and C (later referred to as O). Eventually, a fourth group, AB, was added. Landsteiner and Richter used the same methodology employed in the blood group typing of human blood, blood serum, and other bloodstains, with equally reliable results. By so doing, they opened up the world of forensic science to the use of old evidence to make new identification, or to gain new knowledge about a crime, a crime scene, a victim, or a perpetrator.