Today I got to enjoy giving a lecture with my Sister in Crime, Antoinette Brown, on poisons. She discussed the psychological aspect, and I went over the various types of poisons and how they're treated. So, betwixt us both you see, I have compiled ten questions that as a writer can help to keep things consistent.
1) Why Is your Killer Using Poison?
Is your murderer aged or infirm? Hate the sight of blood? Are they trying to get away with it by establishing an alibi far from time and place of death? Do they want the victim to suffer? (Poisoning can be a slow, agonizing way to die.) Figure out why your murder is using the poison, because that will help you answer the next question.
2) Do they want their victim to die right away or over a long period of time? (Acute or Chronic poisoning?)
Does your murderer want to watch to make sure their victim is dead? Or will they trust to fate? Do they have to kill their victim before a new will is made? This also helps you narrow down your poison choice, so it's something to figure out.
3) Does your Murderer want it to look like an accident or suicide?
In A THOUSAND DEADLY KISSES, my murderer is trying to frame someone for murder. They aren't concerned with making it seem like an accident, so they chose a very 'overt' poison. A poisoner who is seeking to avoid any suspicion of homicide might choose something intended to look more accidental, like poisonous mushrooms given to someone known to go morel-hunting.
4) What kind of poisons does your Murderer have Access to?
If your murderer is a medical professional, they have a wider range of access to various drugs. For example, an oncology nurse might be able to get some radioactive isotope seeds, or a pharmacist would be able to make custom-filled gel-caps, or slip in some similar-looking but far more lethal pills into an order. Does your murderer work in a laboratory that regularly uses cyanide in their experiments? Are they an artist with tubes of Cadmium yellow and Pthalocyanine blue? Are they a delivery driver for a pharmaceutical company? Or are they a housewife who goes for the old standby of rat poison from Wal-Mart?
5) Is Your Murderer trained in Administering Poisons?
If the poison is to be given intravenously, is your murderer capable of using a syringe or a needle? If the poison is being slipped into a capsule, are they skilled at filling capsules? Consider your murderer's education, profession, and skills.
6) Does the victim or the murderer have impaired senses?
Famously, Agatha Christie's Hercule Poirot had one "failure" as a case, involving a blind old lady poisoning a box of chocolates. She was incapable of determining blue from pink, and put the wrong color lid back on the box after tampering with it. If your victim can't smell or taste well, then poison slipped into their food or perhaps into their toiletries might escape detection. If they can't see well, substituting different pills into a pill box, placebos for necessary medication or something more direct could be a safe choice for your poisoner. If your murderer is impaired, they may not be willing to risk certain types of poisons, out of fear of harming themselves by accident.
7) How much Opportunity and Access does your Murderer have to their Victim?
If your murderer is constantly around their chosen victim, then they have more flexibility regarding their choice of poison. If they have access to their private spaces, they could put poison into their shampoo or toiletries, poison a toothbrush, and so on, taking a long time in the bathroom without comment. If they don't visit often, then they might have to bring the poison already prepared. In Agatha Christie's A POCKET FULL OF RYE, the murderer has someone slip a poisoned jar of preserves into the household, thus getting to the victim without ever stepping foot across the threshold.
8) Is the Victim prone to Medical Issues- Allergies, Heart conditions, Diabetes?
If your victim is well known to have an intolerance of certain foods and a gluttony for them, the clever murderer can take advantage of this fact. A careful insertion of peanut-butter into a casserole for someone with peanut allergies, or filling a diabetic's diet coke with sugar and then replacing their insulin with saline? If the victim is a known 'herbal healer', and accidentally dies after a 'hemlock cleanse', well, who would investigate further? Often a victim's weakness can inspire the poisoner's urge to murder.
9) What kind of medical treatment exists for the poison chosen and how fast can help get to your victim?
If the victim lives in a nursing home, then they will likely be checked on at least every eight hours, and medical intervention will begin quickly. If they live alone in a rural area, then help may not arrive until the mailman notices the mail piling up. Research the medical treatment available for a poisoning victim. EMS services now often can begin treatment for poisoning immediately. They are capable of pumping stomachs, inserting breathing tubes, and injecting counter-agents like Narcan for drug overdoses.
10) How much of your chosen poison does it take to hit the LD-50 dose, and how much will your murderer use?
LD-50 is the average lethal dose, or the amount that will kill 50% of its average victims. If your poison requires your victim to eat an entire cupful to die, you may want to consider something more toxic as your poison of choice. If the LD-50 is very, very small, like a single cyanide pill of James Bond fame, then your murderer doesn't need to get very much.
As for researching poisons, these links could prove helpful!
1.h2g2 - Hitchhiker's Guide to the Galaxy
Infamous Historical Poisoners
Alphabetical List of Lethal Poisons
3.Agency for Toxic Substances and Disease Registry
4. American Association of Poison Control Centers
5. American College of Medical Toxicology
Professional nonprofit association of physicians with recognized expertise in medical toxicology
6. Chemical Emergency Poison Control
Nation-wide Toll-free Poison Center Number 1-800-222-1222
Provides callers with reliable information about poison exposure
7. Poison Prevention Education web site
8. World Health Organization
Basic analytical toxicology
9. Poisons: Sinister Species with Deadly Consequences by Dr. Mark Siddall
10. Book of Poisons: A guide for Writers by Serita Stevens and Louise Bannon, 2007, Writer’s Digest Books11. The Poisoner’s Handbook: Murder and the Birth of Forensic Medicine in Jazz Age New York by Deborah Blum