Of course, the risk with ruses and “sleights of hand” is that they can seem improbable if they’re not well-written. After all, the police, and even private investigators, are limited as to what they can do to catch a criminal, and many police detectives understand that if they don’t follow policy when they go after a suspect, the suspect goes free, even if she or he is guilty. That doesn’t mean, though, that sleuths don’t resort to trickery now and again to “catch the bad guy.”
Arthur Conan Doyle’s Sherlock Holmes uses trickery more than once in his adventures. For instance, in The Adventure of the Empty House, Holmes is on the trail of the murderer of Sir Ronald Adair, a man who, it would seem, had no enemies and was not involved in anything illegal. Holmes deduces who the murderer must be, and realizes that he, himself, is a target for the murderer. So, he places a cleverly-constructed dummy bust of himself in his parlor on Baker Street, being careful that the room is lit so that the dummy appears in silhouette. Holmes and Watson then hide in a nearby empty house. Sure enough, the killer makes an appearance, and Holmes and Watson are able to catch the criminal when he tries to shoot the figure he thinks is Holmes.
Agatha Christie’s sleuths resort to sleight-of-hand and ruses in several novels. For example, in 4:50 from Paddington (AKA What Mrs. McGillicuddy Saw!), Elspeth McGillicuddy is on her way by train to visit her friend, Miss Marple. At one point, her train passes another train going in the opposite direction. Mrs. McGillicuddy glances into the window of the other train and sees a woman being strangled. Shocked, she tells the police as soon as she can, and the police begin to look into the case. However, there is no body, there is no evidence of a crime, and no-one has reported a death or missing person. So it seems that Mrs. McGillicuddy was either fabricating her story or was dreaming or was simply mistaken. Upset that no-one seems to believe her, Mrs. McGillicuddy asks Miss Marple for help, and Miss Marple agrees. Assuming that Mrs. McGillicuddy was right, the only place a body could have been disposed of is Rutherford Hall, so Miss Marple gets an acquaintance, Lucy Eyelesbarrow, to take a position there. Eventually, with the help of Lucy’s keen eyes and ears, Miss Marple deduces who the killer must be, and she lays a trap. One day, she arranges with Lucy to be invited to tea at Rutherford Hall. Mrs. McGillicuddy is also invited. During tea, Miss Marple pretends to choke on a bone. When the killer comes to her aid, Mrs. McGillicuddy is able to recognize the killer’s hands and make an identification.
Hercule Poirot, too, sometimes resorts to trickery to catch the criminal. For instance, in Three Act Tragedy (AKA Murder in Three Acts), Poirot investigates the murder of Stephen Babbington, a beloved local clergyman. Babbington dies of a poisoned cocktail during a party that Poirot is also attending, so it’s not long before Poirot is asked to help find the killer. While he’s investigating, another murder occurs, bearing the same hallmarks as Babbington’s death. Once Poirot figures out who the criminal probably is, he arranges a sherry party, to which all of the guests who were at the original cocktail party are invited. During the sherry party, Sir Charles falls over, apparently another victim of the criminal. Everyone’s furious with Poirot for playing a cruel hoax when Sir Charles stands up and admits that he and Poirot planned the “death.” Poirot’s used the trick, though, to find out some important information that helps him to be certain who the killer is.
Ellery Queen and his father, Inspector Richard Queen, use a trick to catch a criminal in The Roman Hat Mystery. In that novel, the Queens are investigating the poisoning murder of Monte Field, a shady attorney with a reputation for blackmail. Field died while he was attending a play, so the Queens visit the theater and begin to look into the connections that Field had with the theater staff, the actors and even some of the other patrons. Eventually, they find out who murdered Field. However, there isn’t any real proof – at least not any that would be admissible in court. So the Queens set up a ruse. They lure the killer into trying to commit another murder, using the same kind of poison in the same way. That trick reveals the killer.
Lord Peter Wimsey also uses a ruse in Dorothy Sayers’ Murder Must Advertise, in which he goes undercover as a copywriter for Pym’s Publicity, Ltd. Another copywriter, Victor Dean, was killed there by a fall down a spiral staircase, and the company leadership is eager to avoid a newspaper sensation. Besides, there are strong hints that Dean might have been murdered. So Wimsey investigates, using the guise of a newly-hired copywriter. The trail leads to an employee who’s been paid by a very dangerous drugs ring to use the firm to make connections with local drug dealers. The closer that Wimsey gets to the truth, the more danger he himself is in so, with some help from his friend, Inspector Parker, Wimsey arranges a ruse that helps him escape danger and at the same time, catch the killer.
Alexander McCall Smith’s Mma. Precious Ramotswe uses ruses more than once as she goes about her investigations. In one clever example from Blue Shoes and Happiness, she’s investigating medical fraud. Local nurse Bonitelo Mampodi has asked Mma. Ramotswe to help her find out the real story behind the strange behavior of Dr. Lubega, Mma. Mampodi’s employer. Lubega refuses to let his nurse take and record patients’ blood pressure, even though it’s a very routine task that even beginning medical students can do. Mma. Mampodi has also discovered that the doctor has taken and recorded fraudulent blood pressure readings, so that he can sell expensive blood pressure medication. Mma. Ramotswe decides to get some concrete evidence, so she makes an appointment with Dr. Lubega. Lubega tells Mma. Ramotswe that her blood pressure is dangerously high and sells her the expensive medication that he’s been selling to other fraud victims. Mma. Ramotswe then goes to her friend, Dr. Moffatt, with the pills she was sold. She finds out that not only was she sold pills that she didn’t need, but she was actually given inexpensive, generic pills in place of the expensive medication for which she was charged. In the end, Mma. Ramotswe’s trickery, together with help from Dr. Moffatt, prove Dr. Lubega’s fraud and he’s reported to the Ministry.
Sometimes, the sleuth has to think fast, and isn’t able to use a pre-planned ruse. That’s what happens in Tony Hillerman’s The Ghostway. In that novel, Jim Chee, a Navajo Tribal Police officer, is looking for Margaret Billy Sosi, a missing Navajo teenager. Chee believes that her disappearance is connected to the murder of Albert Gorman, a Los Angeles Navajo who’s moved to the Big Reservation. So, against orders, Chee goes to Los Angeles to try to find Gorman’s killer and to track down the missing girl. Chee finds out where Margaret’s been staying, and is waiting for her to return there when he sees her about to get into a van driven by Gorman’s killer. Desperate to keep Margaret safe, and determined not to let her out of his sight, Chee thinks quickly and is able to come up with a clever trick. He pretends to be very drunk and lurches towards the van, distracting the driver. He manages to wangle his way into the van, and even though he’s now in danger, he gives Margaret just the time she needs to escape.
There are, of course, lots of other ruses, tricks and “sleights of hand” that sleuths use to catch criminals; space doesn’t permit me to mention them all. And let’s not forget the “sleights of hand” that criminals use, too (but that’s a topic for another post). Which sleuths’ tricks do you think have been the cleverest?