Mystery Commandment #1

In this series, I will be examining the Mystery Decalogue of Fr. Ronald Knox.

The first commandment of mystery fiction is:

I. The criminal must be someone mentioned in the early part of the story, but must not be anyone whose thoughts the reader has been allowed to follow.

In his 1939 commentary on his Decalogue, Fr. Knox said:

The mysterious stranger who turns up from nowhere in particular, from a ship as often as not, whose existence the reader had no means of suspecting from the outset, spoils the play altogether. The second half of the rule is more difficult to state precisely, especially in view of some remarkable performances by Mrs. Christie. It would be more exact to say that the author must not imply an attitude of mystification in the character who turns out to be the criminal.

The spirit of the first part is, I think, fairly obvious: the reader must have some chance of figuring out the solution and having some idea that the character who turns out to be the murderer exists is a necessary (though not, except in badly written mysteries, a sufficient) condition for that.

There is, however, an exception to this rule: where the specific identity of the murderer is of no great consequence. If the solution to the problem is some salient characteristic of the murderer, rather than his name, it is fair play to have not introduced his name before so long as the salient characteristic was introduced. For example, if the conclusion of the mystery is that it must have been a policeman who committed the crime, it’s not cheating to have not mentioned the particular policeman before. I should note that this regards the actual plunging of the dagger; it won’t work if the policeman acted alone. It does work, however, if the policeman was acting on behalf of a character we’ve already met.

So a possible reformulation of the rule is that at least one of the criminals must have been mentioned in the early part of the story. If the murderer acted alone, this becomes the rule which Fr. Knox set down. In the case of conspiracies, however, one can omit the pawns from appearing in the early part of the story. One cannot, however, omit them entirely. If the dagger was plunged into the victim by the man cleaning his chimney acting in the pay of his nephew, we do not need to meet the chimneysweep early on, but we do need to learn fairly early on that he had his chimney swept.

I should note that it is less tricky to pull this off if the Chimneysweep turns up dead halfway through the novel.

With regard to the other half of the rule, I think that Fr. Knox’s clarification—that the author must not imply an attitude of mystification in the character who turns out to be the criminal—is quite right. To do this would be to lie to the reader. There is a genre called the unreliable narrator genre, of course, but I’ve never heard of this being done well in mysteries.

(The problem is that nothing can compel the unreliable narrator to eventually reveal the truth. You could, however, have multiple narrators. Probably the best example would be the memoirs of the murderer, which contain lies that misdirect the reader, followed by a postscript explaining which parts were lies, written by the police detective after the murderer’s execution.)

Probably the book which Fr. Knox is referring to, by the way, is Agatha Christie’s The Murder of Roger Ackroyd. (There’s no point in spoiler warnings since the context inherently gives away the plot twist.) It is narrated by Dr. Sheppard, who assists Poirot in his investigations, and rather famously concludes with Poirot identifying Dr. Sheppard as the murderer. Christie makes it work by having the novel being written in real-time during the case; thus when Poirot reveals that Dr. Sheppard was the murderer the novel was almost entirely finished; he needed only some minutes to complete it where he admitted his guilt. And it should be noted that Sheppard was chronicling what Poirot did and said, he was not himself actively engaged in trying to solve the crime.

This does raise a curious point, though, that the attitude of mystification which is forbidden is in the murderer’s private thoughts—whether known through omniscent narration or first-person narration—not in the murderer’s actions. It is perfectly permissible for the murderer to have the external attitude of mystification. In fact, it is fine for the murderer to actively investigate the crime in order to throw suspicion off of himself.

I will say, though, that on the last part I tend to find that ruse disappointing. I prefer mysteries in which the good guys are actually good. I realize that in a sense this goes against the heart of the mystery novel—which is figuring out which apparently good person isn’t—but I prefer a mystery story in which there is some solid foundation in the rough waves of deception.


If you like murder mysteries, you might like murder mystery, The Dean Died Over Winter Break.

The Detective Decalogue of Fr. Ronald Knox

If one reads about the golden age of detective fiction (roughly, the inter-war period, circa 1919-1939), one is apt to come across some of the formulations of rules for detective fiction written then. As I’ve noted, detective fiction has from its inception been a self-referential genre, and it was talked about even more outside of the pages of the mystery novel than inside them.

One of the most famous lists of rules is the Decalogue (ten commandments) set down by Fr. Ronald Knox. They are:

1. The criminal must be mentioned in the early part of the story, but must not be anyone whose thoughts the reader has been allowed to know.
2. All supernatural or preternatural agencies are ruled out as a matter of course.
3. Not more than one secret room or passage is allowable.
4. No hitherto undiscovered poisons may be used, nor any appliance which will need a long scientific explanation at the end.
5. No Chinaman must figure in the story.
6. No accident must ever help the detective, nor must he ever have an unaccountable intuition which proves to be right.
7. The detective himself must not commit the crime.
8. The detective must not light on any clues are not instantly produced for the inspection of the reader.
9. The stupid friend of the detective, the Watson, must not conceal from the reader any thoughts which pass through his mind: his intelligence must be slightly, but very slightly, below that of the average reader.
10. Twin brothers, and doubles generally, must not appear unless we have been duly prepared for them.

I propose to go through each of these in one post per rule (which I will eventually link here) and discuss them. In aid whereof, this page which has some of Fr. Knox’s own commentary on his rules (years after he wrote them) will be especially interesting.

I should note that in general I agree with the Decalogue. My intention is not criticism but consideration—to look at the purpose of the rule and as such when it can be broken in good faith.

Murder By Poison

Though I’m only about halfway through writing Wedding Flower Will Do for a Funeral (the second Chronicle of Brother Thomas), it’s good to put some thought into when the next book will be—murder mystery plots are the sort of thing it’s nice to kick around for a while instead of having to come up with in a moment. Accordingly, I bought a book on poisons for mystery writers. I hope to review when I’m done with it, but I wanted to talk about the subject of poison as the murder weapon.

(I should note that this is thinking out a variety of alternatives, and is not aiming at any single conclusion; it’s more like a walk through a workshop than an essay.)

Poisons kill, but they do so in a variety of ways. Some kill quickly, others slowly. Some kill very painfully and some just put the victim to sleep and a short time later into eternal sleep. And as I was reading over descriptions of the effects of various poisons it occurred to me that some poisons have greater differences between them than there are between some of those poisons and more conventional weapons such as knives and bullets.

One of the great differences in poisons is a question of detection. That is, how hard is it to discover that the victim was poisoned? Poisons which cause the victim to writhe in agonizing muscle spasms for days before finally killing them, for example, are not likely to be mistaken for death by natural causes. So why use such a poison?

(Before answering that question I should note, in passing, that these tend not to be popular poisons in television mysteries because they don’t give the opportunity for the detective to spot the clues which indicate poison that most people have missed. If the detective confidentially whispers to the police that a victim taken suddenly ill right after dinner and who thrashes about for several days before finally was probably poisoned, he’d be liked to get a sarcastic, “How did you work that out, then?” if it’s a British show or, “Thank you captain obvious” if it’s an American show. Good television, this does not make.)

I think that the best reason to use obvious poisons—except in the case of pure malice, that is, to want to see the victim suffer—is in order to frame somebody. The big problem that murder mysteries have is that of motive. Cui bono? Whose good? Who is it who benefits so much from someone’s death that they’d commit it in cold blood (and murder by poison almost certainly has to be in cold blood since the poison must be procured beforehand). There are generally only a few people who will benefit to any great degree from the death of a person; this narrows the field of suspects down quite considerably. Good for the detective, not nearly so good for the murderer. (And to actually go through with a plan for murder, one must expect to get away with it.)

There is still a problem with the frame-up: if the case against the person being framed isn’t air-tight the field of suspects will become very small indeed. This can certainly be made to work, but poisons introduce the problem that the murderer doesn’t have to be present when the victim takes the poison. While convenient, it renders alibis useless. (This can to some degree be worked around by contriving to make it seem like the time the victim took the poison was known.)

If the murderer is not trying to frame one of the few other people who will benefit from the death of the victim, an obvious murder which does not readily admit of an alibi seems very unlikely to appear a good idea. I suspect, then, that this is probably best used in revenge killings, and in particular those where the relationship between the killer and the victim is not generally known. In English cozies this is the classic case of the killer being the grandson of someone who the victim murdered forty years ago in Australia.

This can be done extremely well; I think most of the interest is going to lie in establishing the backstory and solving a 40 year old mystery in order to unravel the present mystery.

The other sort of poisoning—the gentle kind—results, I think, in a very different sort of murder investigation. Probably the most notable aspect of this is going to be the overturning of an initial conclusion that the victim died from natural causes. The most classic example of this is, I think, the elderly rich relative.

In many stories the climax of the investigation is the digging up of the body and testing it for poison, which is then found. There’s nothing wrong with that plot, but things get very hard if a monkey wrench is thrown into it. The obvious monkey wrench is the undetectable poison—and there are a few—but it’s interesting to consider the approach that Dorothy L. Sayers used in Unnatural Death. It suffered from the minor problem that the effect she relied on was exaggerated about 100-fold; as one reviewer put it the method would work but the apparatus used would be comically large. But that aside, since a poison wasn’t used none could be found. And the rest of the story tells us, I think, how stories about undetectable poisons have to go.

If the first murder was undetectable, the only real solutions is for there to be more murders, this time imperfect. The murderer had ample time and opportunity to plot the first murder, but latter ones will either be rushed or the murderer will relax because of the overconfidence created by success.

The murderer can be pushed into subsequent, rushed murders either by the detective—who seems to be getting too close—or by someone who witnessed an incriminating part of the murder and is now blackmailing the murderer. (It’s convenient for detectives how few fictional people realize that blackmailing a murderer is a very dangerous way to make money.)

In the former case, this can be done by way of the murderer having an unwitting accomplice—somebody who didn’t understand the significance of an action they knew the murderer did or may have even done at the murderer’s request. The impetus comes when the detective is starting to ask questions which might make the unwitting accomplice realize the significance of what they know. The tricky part about this is that the detective can’t do this on purpose or he’s guilty of the unwitting accomplices’s death. It’s not easy to pull this off even unintentionally, though, since the brilliant detective should—because of his brilliance—foresee the probable outcome of asking the questions he’s asking.

All things considered, I think the cleaner way is for the second victim to blackmail the murderer. The downside is that the detective is thus being handed a piece of luck outside of his control, which isn’t satisfying. On the other hand, this is true of (basically) all possible clues. The murderer’s bad luck is the detective’s good luck. If the murderer committed the perfect murder, the detective couldn’t solve it.

On the one hand, this feels like a cheat. On the other hand, it is appropriate; to murder is imperfect and imperfect people do not do things perfectly. Murder is a sort of short-cut, and people who take one short-cut will take others, too. The real trick is to keep the sort of short-cuts taken that help the detective in-character with the murder itself.

Detective Sidekicks

In his Decalogue (ten commandments) for detective fiction, Fr. Ronald Knox’s ninth commandment was:

The stupid friend of the detective, the Watson, must not conceal any thoughts which pass through his mind; his intelligence must be slightly, but very slightly, below that of the average reader.

The Watson in a detective story is generally understood to be a stand-in for the reader, and not without reason. I’ve been wondering how necessary a Watson character is, so I’d like to look at the functions of a Watson:

  1. To have someone to whom the detective must explain this thinking and actions.
  2. To have someone for the detective to talk to.
  3. To have someone who looks up to the detective.

Regarding the first, it can be very helpful for the detective to need to explain himself. How the detective thinks is interesting and apart from having to explain himself we mostly won’t know. It is always possible to give him a habit of thinking out loud, of course; one sees this a bit with Chesterton’s Father Brown (who generally doesn’t have a Watson character).

Regarding the second, this is acknowledging the truth that it is not good for man to be alone. But the companion of a detective does not need to be a reader stand-in and often is better if he isn’t. My favorite example of this is Harriet Vane in the Lord Peter Wimsey mysteries. She’s not on Lord Peter’s level, but she’s also not—generally—a reader stand-in.

I should mention that Harriet Vane only appears in 4 of the Lord Peter books; Lord Peter’s companion is more often his friend, Charles Parker. Parker is more of the typical Watson character; I suppose my marked preference for Harriet Vane is sufficient to give my opinion of this.

Regarding the third quality of a Watson, this gets to a somewhat tricky aspect of art—most of conveying grandeur is done not by conveying it but by conveying how people react to it. Grandeur is a very difficult thing to show; people being impressed is much easier to show. Perhaps one of the best examples of this is the line, supposedly said by Katherine Hepburn, describing Fred Astair and Ginger Rogers, “He gave her class and she gave him sex [appeal]”. It’s true, though not literally so.

Fred Astair had sex appeal, but Ginger Rogers (in how she acted her roles, I mean) recognized it and made it intelligible; she reacted to him as if he had sex appeal, making it clear he did. Ginger Rogers had class, but Fred Astair (again, in how he acted in his roles) treated her as if she was classy, making it clear to the audience that she was. Much of either—how we in the audience know them—is by the reactions to them.

And so it is with the brilliance of the detective. The detective must actually be brilliant or the Watson will only come off as a farce. But if the detective is brilliant, the Watson failing to understand and being enlightened will show the detective’s brilliance off.

Now, when it comes to how necessary these are, I think that the second—companionship—works fairly well, if not better, with an equal. The first and third do require someone who is not an equal, but they don’t need to be an associate of the detective. There will always be bystanders present who can take an interest in what the detective does, and he will suffice to ask questions and be impressed. There is even a potential benefit to this approach in that Watson might be a one-off, but if the detective is constantly running into people who are impressed with him, it lends credence that this is the normal reaction to him.

Of course, the two can be mixed; third parties can relieve the Watson of his duties on occasion in order to spread the work around.

I don’t really have a conclusion, here, other than to say that I don’t think that a Watson is strictly necessary. They’re a good option, but not, I think, a requirement.

The Implausibility of Large Conspiracy Theories

Conspiracy theories are very curious things in that they are superficially ridiculous but can suck people in if they can get past that. And I think those things are related.

One of the best descriptions of God comes from a letter of Saint Paul: “He who accomplishes all things according to the intentions of His will”. It’s a marvelous contrast to human beings, who accomplish very little according to the intentions of our wills; our successes are usually only partial successes. And this is where the superficial ridiculousness of conspiracy theories comes from.

Conspiracy theories all assume hyper-competence on the part of the conspirators.

This is why it’s so hard to put into words why a conspiracy theory is ridiculous: it’s because of all the multitude of things which had to go right in order for the conspiracy to succeed.

This is also why it’s so hard to argue a conspiracy theory. Any one thing which had to go right can be explained away; it’s all of them put together that just get ridiculous.

I think this is also why, if one can get past that initial instinct to just laugh, conspiracy theories can suck people in. They’re a bit like mystery stories, but on steroids. As long as one considers the pieces in isolation, each one is a puzzle to solve where you get to match wits with someone really clever.

It’s that in isolation part which is so critical, though. There’s actually a similar problem when watching a long-running show like Murder, She Wrote. (A show I dearly love, I should add, and for me some formative fiction.) On any given episode, it’s reasonable enough that a murder mystery writer should happen to be present at the scene of a cleverly committed murder. That it happened 263 times defies belief. Hence all of the jokes about how Jessica is a serial killer who framed others for her crimes.

(It should be noted that the joke of Jessica being a serial killer is not viable given that almost every episode ends with the killer confessing.)

Large conspiracy theories are ridiculous because they’re like being presented the entirety of Murder, She Wrote all at once.

A Medieval Satirical Love Poem

Today at A Clerk of Oxford, she posted a medieval poem which satirizes the romantic poems popular at the time. It may take a few readings to be able to deal with the unusual spellings, but it’s worth it because the poem is quite fun.

This may be my favorite stanza from it:

Whosoever wist what life I lead,
In mine observance in divers wise;
From time that I go to my bed
I eat no meat till that I rise.
Ye might tell it for a great emprise, [triumph]
That men thus mourneth for your sake;
So much I think on your service,
That when I sleep I cannot wake.

One of the two books in which this poem is found was in a commonplace book owned by a grocer, in the 1500s. It’s also fun to see, though the expression is somewhat different, the sense of humor is very much the same as what one might get from Chesterton or even a more modern wit.

Just to illustrate my point, compare this with Chesterton’s poem The Logical Vegetarian:

You will find me drinking rum,
    Like a sailor in a slum,
You will find me drinking beer like a Bavarian
    You will find me drinking gin 
    In the lowest kind of inn
Because I am a rigid Vegetarian.

Time Wears On Us All

My furnace has recently been failing to heat the house, and after a bit of investigation I discovered that the fault was in the inducer motor. (The inducer motor powers the fan which induces, i.e. sucks, the air through the combustion chamber.) I did some lubrication and manipulation of it, which managed to coax it into working for another day or two until a new motor arrived.

Replacing it turned out to be about maximally difficult; the inducer fan had rust-welded onto the shaft and even copious amounts of WD-40 specialist rust remover did nothing to loosen it. I eventually had to drill out not only the screw which held the fan onto the motor shaft but the motor shaft itself, then I had to resort to using a claw hammer to pry the thing off. Once that was done taking the old motor off and putting the new motor (and new fan which I had fortunately thought to also purchase, just in case) was the work of a few minutes.

Once my furnace was back to heating the house I turned my attention to the motor, because I was very curious what was wrong with it. From the occasional screeching sound, the help of lubrication, and the fact that once in a while turning it backwards allowed it to start spinning freely in the correct direction, I had thought that a piece of metal debris had gotten lodged in the motor.

It turned out to be wrong.

It was actually that one of the two bearings on which the motor shaft rested had rusted out and disintegrated to the point of no longer working.

If you’re not familiar with how a bearing is constructed, there is an inner sleeve and an outer sleeve. These sleeves are held apart by a number of balls. The outer sleeve rotates against the inner sleeve by rotating these bearings; they reduce the friction of rotation because—being spheres—a tiny fraction of them is actually in contact with either the inner sleeve or the outer sleeve. Moreover, they allow the two sleeves to rotate relative to each other by rolling along both, rather than by the sleeves rubbing against each other. They’re ingenious inventions.

There is, however, the problem of keeping the balls between the sleeves. This is done with some walls and also with what one might call a retaining bracket. If you look, you can see that the retaining bracket on the ball bearing of my motor had rusted into nothing in parts (specifically, the lower right part). Actually, that’s probably not quite true; I suspect it had mostly rusted by some small parts hadn’t rusted but instead got caught into the balls, preventing them from rotating smoothly. That would explain why counter-rotating it might occasionally allow the shaft to spin freely—it would have dislodged the tiny bits of metal and moved them to somewhere harmless. Until they fell back in the way, again. Which in practice seemed to be every few hours.

This is the problem with metal—it is very hard, but it is dead. It cannot repair itself from the wear-and-tear of life, so it eventually fails. In theory one could have taken the motor apart and thoroughly cleaned it, periodically, to prevent the build-up of the sort of grime which causes rust, but this is still a living thing fixing a dead thing.

This is the curious thing about life. All things are dying, and can only survive by being continually renewed. Avid fans of Chesterton will note this as Chesterton’s Post:

We have remarked that one reason offered for being a progressive is that things naturally tend to grow better. But the only real reason for being a progressive is that things naturally tend to grow worse. The corruption in things is not only the best argument for being progressive; it is also the only argument against being conservative. The conservative theory would really be quite sweeping and unanswerable if it were not for this one fact. But all conservatism is based upon the idea that if you leave things alone you leave them as they are. But you do not. If you leave a thing alone you leave it to a torrent of change. If you leave a white post alone it will soon be a black post. If you particularly want it to be white you must be always painting it again; that is, you must be always having a revolution. Briefly, if you want the old white post you must have a new white post.

He went on to note, by the way, that these is as true of human institutions as it is of material objects; this is a curious property of our universe—truths always have echoes. You can find this idea in C.S. Lewis’s essay Myth Became Fact, but you can also find it in real life. I once had a pumpkin which grew large and looked beautiful but when I went to harvest it it had turned out that mice had eaten almost the entire thing from the back and inside. It’s a wonderful metaphor for all sorts of things—modern universities, for example—but it also was a very disappointing event in my garden, years ago.

Our universe is full of echoes.

Edit: as Mary in the comments pointed out, the story I quoted is Chesterton’s Post, not Chesterton’s Fence. (Thanks, Mary!)

A More Modern Recording Alibi, Still Feels Wrong

This is an follow-up to Alibi by Recording. Discussing that post on Twitter made me think of a more modern version of using a recording to convince someone that the murderer is in a place when he’s actually somewhere else committing the murder.

Instead of merely recording a conversation which would be overheard, the murderer could record a series of responses and use voice recognition to map a tree of responses to what a microphone hears. Thus the murderer could actually have a conversation with someone—through a locked door. Something like this:

Janice: [knocks] Are you working late again?

Bob: Yes. I have to get these reports done for tomorrow.

Janice: Can I get you some coffee?

Bob: No thanks, I already got myself some coffee. In the big mug. It’s going to be a late night.

Janice: OK, I’ll leave you to it.

Bob: Good night.

Janice would swear to the police that she had a conversation with Bob while Bob was really off murdering his Aunt for the inheritance she was leaving him. Since these sorts of programs can have a history, it could eventually go to some default response like “I’m sorry but I have to concentrate on work. I’ll talk to you in the morning.”

Not foolproof, of course, but that most interesting murders are at least a little bit daring.

I still think that this would be a completely unsatisfying reveal to a modern audience. And yet it would be very directly analogous to, say, the murderer of Roger Ackroyd using a phonograph of the deceased to convince people that the deceased was alive when he was already dead (as happened in the Poirot story, The Murder of Roger Ackroyd).

And I maintain, as I did in my previous post on the subject, that it’s because a technological solution is simply not very interesting. We’ve got technology up the wazoo and back out again, these days. What we find very interesting is the human element.

Alibi By Recording

I was recently thinking about the way that the TV version of Poirot sometimes re-sets the stories in the 1920s. (Poirot stories were generally written contemporaneously, spanning the 1920s through the 1960s.) It makes sense on television for a variety of reasons—including that the 1920s were far more visually interesting than most of the decades which followed. That said, it is curious because the sorts of plots one finds change somewhat over the decades.

Nowhere is this so obvious as in the case of murder by ingenious invention. It was a common enough plot in the golden age of mysteries but seems to have fallen out of favor more recently. And a particular kind of ingenious invention has really fallen into disuse these days: the alibi by recording.

In the golden age of fiction it was a not uncommon plot that either the murder’s presence or the victim’s being alive when he was already dead was established on the basis of an overheard conversation which turned out to be a recording. (Both give the murderer an alibi, though in different ways.)

I’m curious why this has fallen out of fashion. (And of course I don’t mean that it never happens—I can think of a few TV mysteries which have employed the murderer using a recording to fake being on a stage giving a presentation when they ducked out for a minute to commit the murder. But I think that’s more properly regarded as a variant of the being-on-stage alibi rather than the recording-alibi.)

There was a certain amount of fascination with the progress of technology which one finds in the 1920s because it was an era of rapid technological progress. But our era is also one of rapid technological progress. More so, in absolute terms.

I think, though, that we’ve become exhausted with technological progress. It’s not merely that we wonder whether all the change is actually for the better—we do, but so did the people in the 1920s. In many ways more than we do, actually, since they had just come off of the horrors of the first world war and its deadly machines and poison gasses. Nuclear annihilation isn’t much of a threat any more, though technically it is still possible.

It’s also not that technology has become the realm of the specialist. It was always the realm of the specialist. It wasn’t ordinary people who invented gadgets, and it took more expensive equipment to record a phonograph in the 1920s than it does to record voice on a cell phone now.

I think it’s rather that we have a sense that life doesn’t change nearly as much as one would think it does. I don’t mean that life is mostly the same minute-by-minute. That would be ridiculous. We do far more driving and far less walking; we are constantly stimulated by electric devices and never has mediocre music been nearly as omni-present. But we remain human beings with much the same problems; our problems are just far more convenient and fast-paced.

Being so inundated by technology, we find it boring. These days (with expensive software) one could edit video to remove somebody from a security camera recording. So what? That’s not an interesting reveal. It’s really no more interesting than a mystery about wizards involving the reveal that the murderer used an invisibility spell.

What’s far more interesting in murder mysteries is the human element.

I should also note that this is probably also partially a result of short stories being mostly dead and gimmics (by which I mean clever murders) being far more the domain of short stories than they are of novels. Not that the murders in novels aren’t clever, only that they’re not generally based on one large reveal. That said, as I’ve argued in the past, structurally speaking, television murder mysteries are much closer to long short stories than they are to novels. So murder mystery short stories have generally moved to television from the written word.

And even there, recordings are not a popular alibi.

Dysfunctional Families in Murder Mysteries

I was recently watching the Murder, She Wrote episode It’s a Dog’s Life with my eldest son and it occurred to just how much dysfunctional wealthy families are a staple of murder mysteries.

It’s not the wealthy part that’s at all surprising—it’s well known that the two most common motives for murder in detective fiction are sex and money—but the dysfunctional part. Or at least that they’re obviously dysfunctional.

This is probably more a staple of modern detective fiction like Murder, She Wrote than it is of golden age detective fiction, I should add, though one can certainly find it in golden age detective fiction too.

The reason I find it a little surprising is, roughly, two-fold:

  1. It’s somewhat at odds with the idea of concealing the murderer
  2. It makes the victim less sympathetic

Curiously, that last part is papered over quite frequently—almost as if the authors don’t notice it. But it’s simply not avoidable. One child turning out badly could be attributable to free will but a parent who badly spoiled all his children is, simply, a bad parent.

You can see this same problem in The Big Sleep. The old man who hires Philip Marlowe was—according to the story, and if I recall correctly, according to the old man himself—a radically selfish man who didn’t actually raise his own children. Granted, in that story the wayward child didn’t kill its father, but still, it made the old man very unsympathetic. It also made Marlowe’s loyalty to him incomprehensible. Why be loyal to a man who’s only reaping the results of his own bad behavior?

The other problem with with this approach is that—however suited it is for coming up with a convincing murder—it makes for unpleasant detection. If everyone is distasteful, the story of finding out which of them committed the crime will be distasteful, too. The solution to this is frequently to have a lone sympathetic character in the story, but this also raises problems.

The first and most obvious is what on earth the sympathetic person is doing in the company of the others. Decent people rarely associate with awful people for the pragmatic reason that awful people try to drag everyone else down with them. There’s also the somewhat more subtle psychological fact that awful people rarely like decent people. And if they’re thrown together by being in the same family, this then requires an explanation of why on earth one turned out differently than the rest. (I think that having different mothers or different fathers is a semi-common solution to this problem, but it introduces real issues of judgment. There’s no judgment call more important than picking a good parent for your children.)

Getting back to the first point, there’s also the issue of creating overly obvious suspects. The wife and child of a rich man are the obvious suspects in a murder mystery under any conditions—the eternal question is cui bono? (Who benefits?) So in a sense making the family dysfunctional is shifting the question from “could it be them” to “is this a head-fake or a double-head-fake?” Which is a legitimate sort of mystery, but it is a bit limiting because it means the story almost certainly will focus on opportunity and alibis. I will grant, however, that it can be a good way of distracting from other people with motives—inheritors are not always the only people who benefit from a rich man’s death.

None of the above is meant to say that this situation cannot be made to work, only that it’s got some inherent difficulties that are often overlooked.