It’s very difficult for a killer to commit murder without leaving some sort of “signature.” I’m not talking about forensic details such as DNA, fingerprints and so on, although certainly that kind of evidence is important. I'm also not referring to the kinds of "signatures" that many serial killers leave and that get so much media attention. Rather, I’m talking more about the kind of crime that’s committed, and the way the murder occurs. In real life, for instance, it’s difficult to strangle someone with a piece of his or her own clothing if the murderer doesn’t know the victim, unless the murderer is large enough to overpower the victim. If there are no signs of struggle, there’s no guarantee, of course, but it’s likely that the victim knew the murderer. Those kinds of hallmarks and “calling cards” give the sleuth a place to start searching for suspects in real life and in well-written crime fiction.
There’s a fascinating example of a certain kind of crime in Tony Hillerman’s The Ghostway. In that novel, Jim Chee, one of Hillerman’s sleuths, is paired with an FBI agent to try to find Albert Gorman, a Los Angeles Navajo who’s just returned to the reservation. Gorman’s wanted for a shooting death, and Chee’s asked to bring him in. When Chee arrives at the home where he thinks Gorman’s staying, he discovers Gorman’s body. What’s interesting is that Gorman’s body has been prepared for burial in the traditional Navajo way. At first, then, it looks as though his killer is a Navajo. But a few “wrong” details convince Chee that he’s looking for a non-Navajo who’s learned enough about Navajo customs to try to make it look like a “local” murder. In this case, the killer’s "signature" is that of an informed (but not well-enough informed) “outsider.”
Agatha Christie’s Hercule Poirot is an expert at using these “calling cards” to uncover murderers. I’ll just give three examples. In The ABC Murders, a series of murders is committed in and near some popular seaside resorts. The police and the public think it’s the work of a serial killer; in fact, the investigative team includes an expert in serial killings. But Poirot focuses on the kind of person who would be able to commit the crimes. For instance, the second murder is of Elizabeth Barnard, a young, flirtatious waitress whose strangled body is found on the beach one morning. Her tendency to flirt and enjoy men’s attention, plus the fact that she was strangled with her own belt, leads Poirot to believe that the killer has to have been someone who’s attractive to women and whom the victim would have thought interesting. That “hallmark” is part of what leads Poirot to the real killer.
Poirot uses “hallmarks” to find a killer in Evil Under the Sun, too. In that novel, Poirot is taking a holiday at the Jolly Roger Hotel, off the Devon coast. So is beautiful, notorious Arlena Stuart Marshall, her husband Kenneth, and her stepdaughter Linda. Late one morning, Arlena’s strangled body is found on the beach at Pixy’s Cove, which is an islet not far from the hotel. At first, it seems that her husband might be responsible for the killing. After all, she’s been having a rather obvious affair with another guest at the hotel, and Kenneth Marshall’s account of himself doesn’t hold up under scrutiny. But certain aspects of the case convince Poirot that this wasn’t a crime of sudden anger. The timing of the crime and the fact that the killer had to know the area very well, among other things, tells Poirot that the crime was a well-planned murder by someone who’s killed before.
In Appointment with Death, Poirot investigates the murder of a tyrannical matriarch while she and her family are on a trip to Petra. At first, her death is put down to heart failure since she was elderly and the trip was physically stressful. When it turns out that she died of an overdose of digitalis, Poirot has to find out who administered it. The victim’s entire family falls under suspicion, since she’d mentally abused all of them. One aspect of the murder, though (I don’t want to give away spoilers), convinces Poirot that the crime isn’t that simple, and it’s that “hallmark” – the mark of a non-family member – that points him closer to the truth.
We also see how the sleuth uses the “hallmarks” of a killer in Emma Lathen’s Murder to Go. That’s the story of a fast-food company, Chicken Tonight, that’s gotten some recent popularity and new franchisees. Chicken Tonight’s specialty is roasted chicken in many different flavors, including brand-new Chicken Mexicali. Things are looking up for the company and its franchisees when all of a sudden, customers begin dying after eating the restaurant’s food. John Putnam Thatcher’s bank, Sloan Guaranty, has $12 million invested in the company, so he wants to find out who’s behind the poisonings before the company has to close altogether. Everyone’s relieved when suspicion falls on a disgruntled former employee, Clyde Sweeney, who has a bad reputation and access to the warehouse that’s the source of the poisoned food. Sweeney’s gone into hiding, too – just exactly what you’d expect from a guilty person. Thatcher’s not so sure, though. Sweeney is strictly small-time. Besides, this set of poisonings has been well-financed, and Sweeney wouldn’t have been able to manage that. Those “hallmarks” start Thatcher on the path to the real killer.
There’s an interesting example of how a killer leaves a “signature” in Martin Edwards’ The Cipher Garden. At the beginning of the novel, landscaper Warren Howe is murdered with his own scythe while he’s working. Then, his body is left in one of his own trenches. His wife, Tina, is suspected of the killing, but she’s got an alibi, and the police have no grounds for pursuing a case against her. Ten years later, DCI Hannah Scarlett and her Cold Case Review team re-open the case on the strength of a anonymous tip. Howe was murdered by his own implement, so the “signature” here is of a killer who didn’t intend to kill – at first. Whoever killed Howe didn’t steal anything from him, so it wasn’t a robbery gone wrong, either. It’s clues like these that lead Scarlett and Oxford historian Daniel Kind to the conclusion that Howe’s murderer probably knew him and probably hadn’t started with the intention of killing him. Of course, in Howe’s case, that still leaves a wide field….
Also interesting is the “signature” of the killer in Caroline Graham’s Death of a Hollow Man. That novel is focused on the murder of Esslyn Carmichael, leading actor for the Causton Amateur Dramatic Society (CADS). One night, his troupe’s doing a performance of Amadeus; Carmichael has the role of Salieri. The climactic scene where Salieri slits his own throat goes horribly wrong when it becomes all too clear that someone’s replaced the blunted prop knife with a real one. Here, the killer has left a premeditated “signature” since it takes planning to replace a prop knife. The murder also bears the signature of either a member of the cast or the spouse of one, since it would have been noticed if “civilians” went backstage. While that still leaves Inspector Barnaby more than one suspect, it does more or less rule out a killing in sudden anger, murder by a stranger, or an accident.
Sometimes, of course, the killer fakes a “signature” to make a murder look different from the kind of murder it really is. That happens in many novels; I’ll just mention a few. In Ian Rankin’s Hide and Seek, a junkie named Ronnie McGrath is found dead in an abandoned building. At first, it looks like a simple death of a junkie, like so many others. But John Rebus doesn’t think it’s that simple; Ronnie’s girlfriend claims that Ronnie warned her to hide, and told her he was going to be killed. In this case, the killer has disguised the real “signature” of the killing to make it look like an everyday, sordid “junkie death.” There’s also a “forgery” in Exit Music. At the beginning of that novel, poet Alexander Todorov is found murdered in an unsavory neighborhood. His death has all the hallmarks of a brutal mugging, and it’s not until Rebus starts following up on the last day of Todorov’s life that it becomes clear that this murder was something quite different.
What’s your view? Do you look for the killer’s “signature” when you read crime fiction? Do you usually “read it” correctly?