Murders tend to have distinct signatures. The kind of murder that’s committed often (‘though of course, not always) gives a clue about how well-planned the murder was, how well the murderer knew the victim, and sometimes, something about the murderer’s characteristics and background. The signature that’s most often associated with a poisoning murder is that it’s preplanned, and by someone who knows the victim and has a personal reason for the murder. Poison is also often a clue that the murderer knows at least a little about poison and chemicals. So in a poison murder, it’s not easy for the killer to “hide behind” theories such as self-defense, an unpremeditated killing (which might result in lesser charges than first-degree murder), or a claim that the killing was impersonal (e.g. a burglar who’s surprised by the homeowner). Since poisoning murders are rather risky in that they can point quickly to the murderer, why is the poisoning death so popular in crime fiction? Is it realistic that someone, knowing the risks, would poison another person?
One reason for which poison’s such a popular kind of crime in mystery stories may be that, with comparatively little knowledge, it’s easy to disguise poison as accidental or natural death. That’s what happens in Agatha Christie’s Appointment With Death, in which Hercule Poirot investigates the murder of a tyrannical matriarch while she and her family are on a trip to the ruins of Petra. Mrs. Boynton has a weak heart, and is taking digitalis. When she suddenly dies, her death is at first put down to her weak heart, combined with the effects of the heat and the stress of travel. It’s really the investigating officer’s sense that “something isn’t right” that suggests anything else. That’s also what draws Poirot into the investigation. As a matter of fact, several of Christie’s novels deal with poisoning; during World War I, she worked in a dispensary, and the knowledge she gained from that experience is often reflected in her writing.
In Kaitlyn Dunnett’s Scone Cold Dead, the second of her Liss Maccrimmon mysteries, there’s an attempt to pass a death off as an accident. Macrimmon’s former Scottish dancing troupe is on a tour, and she’s invited the group to make a stop in her hometown, to which she’s retired after an injury. In honor of the group’s visit, Macrimmon arranges for a cocktail party with some traditional Scottish dishes. At the party, the troupe’s manager, Victor Owens, suddenly dies when he eats a scone with mushrooms, to which he’s fatally allergic. At first, it’s believed that his death is a tragic accident – he didn’t realize what he was eating until it was too late. However, it’s not long before the police – and Liss – realize this was murder.
Poison is also passed off as an accident in Elizabeth George’s Missing Joseph, in which Inspector Thomas Lynley and Sergeant Barbara Havers try to find out who killed Robin Sage, the vicar of small-town Winslough. Deborah St. James met the vicar when the two of them happened to be viewing the same painting at London’s National Gallery. Distraught about being childless, Deborah’s comforted by what the vicar says about the painting, and persuades her husband, Simon, to take a holiday in Winslough, so that she can see the vicar again and find some peace. When they arrive, they find out that the vicar is dead – apparently of accidental poisoning by hemlock. Simon doesn’t believe the death was accidental, and calls in his old friend, Inspector Lynley, to find out the truth behind Sage’s death. Lynley and Havers find that Winslough is full of deeply-hidden secrets, and that more than one person had a motive for killing the vicar.
Ruth Rendell’s To Fear a Painted Devil is based around a poison murder that’s passed off as a natural death. Patrick and Tasmin Selby are a young, wealthy, but unhappily married couple who live in exclusive Linchester. One evening, they host a birthday party for Tasmin. At the party, Patrick is stung by several wasps that have built a nest in the Selby roof. Although it seems that Patrick will be all right, he suddenly dies. At first, his death is attributed to the wasp stings. After all, everyone at the party witnessed the wasp attack. But Dr. Max Greenleaf, who’s attended the party – and Patrick – doesn’t think so. He becomes a very reluctant sleuth as he tries to figure out who killed Patrick Selby and why.
Even when poisoning can’t be disguised as a natural death or an accident, it can sometimes be disguised as suicide. That’s what the murderer attempts in Agatha Christie’s Hickory Dickory Dock (AKA Hickory Dickory Death), in which Hercule Poirot is called in to investigate some strange disappearances in a hostel for students. He visits the hostel and encourages the hostel’s matron to call in the police as soon as possible. When one of the residents confesses to being responsible for most of the disappearances, everyone thinks the matter is settled – until she’s found dead two days later. At first, her death is put down to suicide. She was upset about the thefts, and she’s left a suicide note. Soon, though, the alert matron realizes what’s wrong with the supposed suicide note, and Poirot realizes he’s investigating a murder.
Gentleman detective Charles Lenox comes to the same realization in Charles Finch’s debut novel, A Beautiful Blue Death. Lennox is a “well-born” man whose ambitions in life are travel and reading. However, as it turns out, he’s a very talented amateur detective who’s been called in more than once by Scotland Yard. When Lennox’s close friend, Lady Jane Grey, asks him to help her find out the truth behind her former housemaid’s death, Lennox can’t refuse her. Prudence Smith, who now serves in the home of George Barnard, has apparently committed suicide by poison. There’s an empty glass, apparently used, and a suicide note, apparently addressed to her fiancé who works in the same home. Lennox, though, notices right away that something’s amiss, and begins to believe that Prudence was murdered. His suspicions are confirmed when he finds out that several members of the household had reasons for wanting Prudence dead. Then another murder occurs, and Lennox is sure that he’s dealing with a killer.
Poisoning is also popular in crime fiction because the murderer can arrange the death to make it seem that anyone could have committed the crime. For example, in Agatha Christie’s Dumb Witness (AKA Poirot Loses a Client), Hercule Poirot investigates the death of Emily Arundell, a wealthy spinster with poor relations. Her death is originally put down to natural causes; however, it’s not long before Poirot realizes that she was poisoned. The manner of her poisoning, though, cleverly hides the real killer – at first. All of the suspects (and there are several, since Miss Arundell had a large fortune to leave) had an opportunity to administer the poison, and it’s difficult to prove – at least at first – which one of them actually committed the crime.
We also see this kind of poisoning in Dorothy Sayers’ Strong Poison, in which Lord Peter Wiimsey meets Harriet Vane. As the story begins, Harriet’s on trial for poisoning her former lover Philip Boyes. The case seems clear-cut, too; Boyes and Harriet had quarreled, and Harriet had arsenic (the poison used in the death) in her possession (ostensibly to do research for a mystery novel she was writing). To make matters worse, Boyes was known to have gone to Harriet’s home on the night of his death, where she served him a cup of coffee. Wimsey attends Harriet’s trial and promptly falls in love with her. When the jury can’t reach a verdict, Harriet is given a new trial, and Wimsey swears he will clear Harriet’s name. With the help of his friend, Miss Climpson, Wimsey finds out that the real killer has cleverly “hidden behind” Harriet.
Of course, murder mysteries that feature poison are often not as dramatic and “action-packed” as are mysteries that feature, say, shooting or a more graphic kind of murder. But they can be very compelling, and allow for lots of “red herrings” and supposedly-innocent suspects. What are your favorite poisonous mysteries?