It’s a fairly general rule in mystery fiction that the murderer doesn’t want to get caught. So most murderers do whatever they can to avoid being suspected. If they are suspected, they do whatever they can to seem innocent. In mystery novels that focus on one or a few murders and a group of suspects, that involves some sort of alibi. Alibis are interesting aspects of crime novels for a few reasons. One of them – the obvious one – is that they protect the killer. It adds to the suspense when the killer’s supposedly unshakeable alibi is shown to be worthless. Alibis also lend a human touch to a crime novel, especially when innocent suspects scramble desperately for an alibi, even though they don’t really need one. We can imagine what it’s like to be suspected of a crime, and we can understand that urge to self-preservation. Finally, alibis can be intellectually interesting and challenging. Keeping one’s mind on who was where, doing what at the time of the murder keeps the reader intellectually engaged, so long as the alibis don’t get overly complex and therefore, distracting.
Some kinds of alibis are logistical. They’re intended to show that a suspect was somewhere else at the time of the murder, and therefore, couldn’t be guilty. This kind of alibi is especially effective when the murder victim is unlikable and all of the suspects have a strong motive for murder. That’s what happens in Agatha Christie’s Appointment With Death. In that novel, a tyrannical matriarch is murdered by an overdose of a fast-acting poison while she and her family are on a trip through the Middle East. All of the members of her family, plus an assortment of other fellow travelers, have a motive for killing her, and very few of these suspects try to hide their motives. What they do try to do is prove that they didn’t have the opportunity to commit the murder. Simon Brett uses a similar strategy in What Bloody Man is That?, in which an obnoxious actor, Warnock Belvedere, succeeds in making enemies of nearly everyone in the cast of a provincial repertory company’s production of MacBeth. When Belevedere is murdered one night after a rehearsal of the play, actor Charles Paris finds that, because he accidentally fell asleep and got locked into the theater overnight, he’s a suspect in Belvedere’s murder. In order to clear his name, Paris has to find out who else had access to the theater after the rehearsal. Again, all of the suspects have a motive; the key for Paris is to upset the killer’s logistical alibi.
Logistical alibis also figure in my own Joel Williams mysteries. For instance, in B-Very Flat, violinist Serena Brinkman dies of anaphylactic shock on the evening of an important musical competition. In that novel, all of the suspects turn out to have a motive for murder, so one key for Williams and the Tilton, Pennsylvania police is to figure out who had access to Serena’s food and drink and the opportunity to tamper with them.
Of course, murderers in this kind of novel take great pains to be sure that they aren’t obviously at the scene of the crime when the murder is committed. One way to do this is to make the time of death appear different from what it really was. After all, even skilled medical examiners can’t always pinpoint the time of death exactly, and murderers take advantage of this. For example, in Agatha Christie’s Evil Under the Sun, Arlena Marshall, a beautiful and notorious actress, is strangled while she and her husband and stepdaughter are on a seaside holiday. At first, it appears that no-one staying at the resort could have been responsible, but as Hercule Poirot is able to show, time is manipulated ingeniously so it provides a solid alibi for the murderer – at first. Time is also cleverly manipulated in Richard Lockridge’s Twice Retired, which centers on the murder of General Philip Armstrong, Chair of the Dyckman University’s Board of Trustees. Assistant District Attorney Bernie Simmons and Lieutenant John Stein are sent to the university to investigate the death, and find among the suspects disgruntled students, a professor who was about to be denied tenure, and some very unhappy family members. What’s really interesting about the alibi that protects the killer (at first) is that it comes from a much distorted sense of time.
One other kind of logistical alibi is to make it seem that the suspect was never at the scene of the crime. For the killer, this means that he or she needs to be in two places at the same time; at the scene of the crime and elsewhere, in a way that provides an alibi. Both Agatha Christie and Martha Grimes use this kind of alibi brilliantly. In Lord Edgeware Dies (AKA Thireen at Dinner), Three Act Tragedy (AKA Murder in Three Acts)(Christie) and The Man With a Load of Mischief (Grimes), the killer deceives the sleuth (at first) by apparently being somewhere else – seen by others – at the time of the crime. I won’t spoil these novels for anyone, but I will say that they all have in common a very similar approach to the challenge of being in two places at once.
Some alibis aren’t so much logistical as they are psychological. Either the suspect wouldn’t have been likely to commit the kind of crime that occurred, or the suspect had no apparent motive to kill the victim. Both kinds of alibis are very helpful when the suspect had the opportunity to commit the murder. For instance, in Agatha Christie’s Three Act Tragedy (AKA Murder in Three Acts), a mild-mannered clergyman, the Reverend Stephen Babbington, is murdered by a poisoned cocktail during a party. All of the other guests had the opportunity to kill Babbington if they were prepared and careful, but not one of them seems to have a motive. He’s led a perfectly blameless life, and few of the other guests at the party even know him. Those who do are on very friendly terms with him. On the surface, it seems that there is no apparent motive, and that alibi protects the killer until Hercule Poirot uncovers the real reason for the murder.
Perhaps the most creative (but potentially dangerous) way to give oneself an alibi is to pretend to be the victim. In this kind of mystery, the murderer either fakes his or her death, poisons him- or herself, or in some other way makes it seem as though someone else is the killer. After all, most of us believe that no-one would willingly go through the trouble, pain and risk of coming close to death. So when someone apparently dies, or is wounded/poisoned, etc., we automatically assume that she or he is another victim. Both Ellery Queen and Agatha Christie use that alibi brilliantly in some of their novels (sorry, no titles this time – I don’t want to spoil the fun for anyone).
Many crime fiction fans enjoy the challenge of sifting through alibis along with the sleuth and trying to find out which one’s false. I know I do. Do you? Or do you prefer the kind of mystery where you know who the killer is, and the suspense comes from the “chase?”