Edmond Locard, founder of the Institute of Criminalistics, developed what has become known as Locard's Exchange Principle. It states that “every contact leaves a trace,” indicating that a criminal will leave a substance of some kind and take away substances during the commission of a serious crime. Traces often refer to samples of a substance, such as paint chips, hair, fibers and fabrics. Crime scenes will commonly contain trace evidence, often caused by the criminal unconsciously coming into contact with surfaces and leaving or picking up trace materials within an area. In 1831 Leuch was the first to note amylase activity in human saliva, which is an important factor for trace evidence. In 1901, German immunologist Paul Uhlenhuth exerted a share of trace evidence by developing the precipitin test for species. In 1910, Victor Balthazard and Marcelle Lambert published "Le poil de l'homme et des animaux", also translated as "The Hair of Man and Animals", which was one of the first successfully written comprehensive studies of hair. This includes numerous microscopic studies of the hair of most animals. As a result, during one of the first legal cases involving hairs, Rosella Rousseau was forced to confess to the murder in 1910. In 1945, Frank Lunquist developed the acid phosphatase test for sperm, which helps find the DNA of a possible criminal . In 1950, Max Frei-Sulzer developed the tape lift method of collecting trace traces to make things like hair or fibers more transportable for investigators. Finally, in the 1960s, Maurice Muller adapted the Ouchterlony antibody-antigen diffusion test for the precipitin test to determine species of different animal types, which refers to the feather test... middle of paper... n, a robe lying on the floor near the body had bullet holes. It was believed that Lazarus used his robe to cushion blows. On March 9, 2012, Lazarus was found guilty of first-degree murder. Lazarus was sentenced to twenty-seven years in prison on May 11. He will be eligible for parole in a minimum of twenty-two years. In conclusion, trace evidence has been and continues to be an important factor in solving crimes. The story of the tracks demonstrated the appreciation of advanced technology and how much easier it is to find a real criminal. Trace evidence is one of the main studies that help prove a suspicion wrong about hair follicles, saliva, body fluids, tissue and much more. Today, traces of evidence still help many investigators find the killer of most crimes, even though it sometimes takes thirty-two years to solve them..