From Lit Reactor:
Give me a decent bottle of poison and I’ll construct the perfect crime. — Agatha Christie
The victim in your latest crime manuscript slips under the bedsheets after drinking a nightcap of cognac, hot water and honey. Unbeknownst to her, the cocktail has been laced with cyanide by her jilted lover. How long before the poison takes effect? How much cyanide would be required for a fatal dose? Does she slip quietly into the afterlife, or convulse violently in agony for hours? Will the poison be detectable in an autopsy?
When writing about poisoning in crime fiction, these are the types of questions you’ll likely have. Toxicology is a complex science and there are a multitude of dangerous drugs, toxins and venoms around us. This article is a guide to help you focus your research and answer these questions if you’re planning on killing your darlings with poison.
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‘Poison’ is an informal term used to describe any substance that can cause death when introduced to the human body. This means snake venom, paint thinner, fentanyl and plutonium are all considered poisons. The possibilities for killing your characters with poison are nearly limitless given the large number of them in our world. But with endless possibilities comes an incredibly wide scope of research. Your first step in narrowing things down will be to choose a poison that suits your manuscript needs.
Availability should always factor into your choice. It would be difficult for a common thug or a jealous spouse to get their hands on a dose of ricin, a vial of cyanide or a nugget of Polonium-210. That’s why most cases of criminal poisoning in North America involve household chemicals or forced overdoses of common medications. Ethylene glycol, or antifreeze, is a dangerous weapon that can be purchased at the gas station. It tastes sweet and can kill even in small doses. Life-saving insulin is found in every diabetic’s medicine cabinet, but a high dose injection can easily be fatal. It can be tempting to choose exotic toxic flowers and rare spider venoms to kill your victims, but sometimes simplicity can be the best answer. Unless your villain is a botanist or a chemical engineer…
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The burden of determining the cause of death in a murder falls with the coroner or medical examiner. With recent advances in forensic and medical technology, very few poisons remain undetectable. Toxicologists may not be able to find traces of the actual poison in the victim after it breaks down, but they will find chemicals and compounds that result when the human body metabolizes a particular toxin.
Link to the rest at Lit Reactor
Of course the limiting factor is the skill of the ME or Coroner AND their budget.
A small town won’t have access to the most modern equipment nor will a part-time ME have the time or experience to do a large number of tests.
Since drug overdoses are more common cause of death than auto accidents in many places, a writer can add a lot of tension to their work with red herrings and under funded morgues.
Years ago my mother bought a book titled Deadly Doses: a writer’s guide to poisons. We kids told her if anything happened to dad we’d know.
I own that one, as well as the re-issue, called Book of Poisons, and A is for Arsenic. It’s only for my books. No, really!