The Chinese used fingerprints as a method of identification as far back as AD 700.
The Chinese, for example, used fingerprinting to identify the identity of some documents in the 700s, but there was no formal system in place for their use. Hsi Duan Yu, a Chinese book from 1248, has the first written record of medical knowledge of solving crime in a description of how to distinguish between strangulation and drowning. It wasn't until the 1800s that we begin to see the formation of forensic science. In 1814, Mathieu Orfila published work on poisons and how they affected animals.
This was the first recorded instance of forensic toxicology and Orfila is known as the father of toxicology. He also made contributions to the development of testing for the presence of blood and he was one of the first individuals to use a microscope to examine blood. In the 1830s, a Scotland Yard investigator became one of the first people to use bullet comparisons to catch a criminal and a Scottish chemist first used toxicology in a criminal court case.