Usually I focus these posts on the criminal justice system in the modern US. But today I’m veering from that a bit to give you a plot bunny. This one might come in handy if you’re writing a historical or spec fic.

We generally think of forensics—the use of science to help solve crimes—as a modern phenomenon. Certainly, in recent years we’ve made much wider and more frequent use of forensics, and science has made huge advancements. But even hundreds of years ago, science was occasionally used in criminal cases.

As far as I can tell, the earliest documented example of this was a Chinese judge named Song Ci, who was born in the late 12th century. He wrote a textbook called Washing Away of Wrongs. Among other things, his book described an early use of forensic entomology, or the use of insects as crime evidence.

Your book’s setting might not allow for state-of-the-art DNA analysis or spectroscopic analysis of paint samples. But even if your book is set in a pre-industrialized locale, you could take inspiration from Song Ci and make use of some scientific detection methods.