Sherlock Holmes, fictional detective created by Aurthur Conan Doyle. who studied medicine with Joseph Bell and admired him for his deductive power and application of scientific methods. Sir Henry Littlejohn taught him forensic medicine. This medical training provided the basis for the character of Sherlock Holmes. Holmes believed in evidence based deduction and the application of scientific techniques such as analytical chemistry and toxicology to solve crimes. The 19th and early 20th centuries saw a revolution in crime solving methods with the emphasis on careful examination of crime scenes and techniques such as forensic autopsies, the use of fingerprints, photography and laboratory analysis. This trend continues for example with the use of DNA which provides a powerful tool in modern crime detection.