Deborah Blum opens The Poisoner’s Handbook with an overview of the history of poisons. Poisons were largely undetectable until the 19th century, leading to their popularity as a tool for murder. However, the discovery of elements in the early 1800s meant scientists could begin identifying poisons, as they were now able to identify the chemical structure that made up poisons and other chemical substances. At first, scientists were only able to identify metallic poisons, such as arsenic. Thus ensued a “cat and mouse game” in which scientists’ newfound ability to identify some poisons would lead murderers to seek out different types of poisons (2). Many killers soon turned to plant-based poisons, but scientists soon discovered means of identifying these as well.

By the start of the 20th century, industrial-made chemicals were widely available in everyday commodities, including medicines and cleaners. Murderers could often exploit such available chemicals as a source of poison. In response, many police turned to the burgeoning field of toxicology, which called upon scientists to analyze dead bodies in search of possible poisons. New York’s own toxicology work began in 1918, when Charles Norris was hired as the city’s “first trained medical examiner” (4).