Ngaio Marsh wrote 32 murder mystery novels – rather fewer than Christie but, nevertheless, after Christie, she was the next most prolific of the Queens of Crime. It is possible, therefore, to analyse her methods without undue danger of introducing spoilers.

Her victims were predominantly male – in 20 of the 32 novels the victim is male. However, this is not true throughout her writing career. As the chart below shows, during the 1960s, the position is reversed and nearly two-thirds of her victims were female. However, she reverted to her preferred male victims in the following decade.

It should be noted that there were only two novels published during the 1980s so, with a victim of either gender in each, one should not read too much into the sex equality of her final decade.

Perhaps more can be read into the polarised split of victims during the 1940s when the preponderance of male victims was greatest. This was, of course, the decade of the second world war, and, consistent with the thesis put forward by many that whodunnits were a classic form of escapism from the realities of life and a source of comfort (with the natural order restored at the conclusion), it may be that the market, which included troops posted far from home, preferred to avoid unsettling thoughts of dangers threatening the domestic security of the wife and mother at home so that female victims were less appealing.

Estimating the age of Marsh’s victims is not straightforward. She rarely explicitly states the ages of her characters and so it is necessary to rely on other clues – such as the age of children (are they school age or adult) or position or status in the work environment, taking into consideration the tendency for people to achieve positions of authority in middle age in the period when Marsh was writing rather than at the younger ages which might apply in our own era. However, the interests and pastimes enjoyed by the characters must be read as clues to their age with a cautious eye on the tendency for people to adopt middle-aged attitudes and demeanour at rather younger ages than we might expect now.

With these caveats in mind, it is possible to estimate the age of Marsh’s victims and conclude that the average age of the victims was 47. In order t avoid spurious accuracy, it might be better to express this as “late 40s”.

Perhaps more intriguing is the arc which the age of Marsh’s victims describes across her career.

There is a steady increase in the age of the victims from the early novels through to the 1950s. Over this period, she writes victims who tend to be older than herself but, once reaches her 50s (she was born in 1895) the pattern reverses and the victims tend to be younger than herself, and by a growing margin. It is as if she mentally is avoiding confronting her own mortality by having deaths occur to people older than herself and pushes this out for some time but, once she accepts that she is growing ever closer to the inevitability of her death, she can then reverse the process and allow progressively younger deaths in her fiction.

In the cozy world of Golden Age detective fiction, it is perhaps unsurprising that the majority of victims are from the middle class who form, perhaps, the greatest part of her target audience.

However, for me, it is when straying from this convention, with her working class victims, that Marsh is at her strongest in creating an emotional response of sympathy for the victim rather than generating the more usual intellectual stimulus of a challenging puzzle to solve.

If we turn our attention from the victim to the perpetrators, we find that, once again, the majority are male with 26 out of the 32 books featuring a male murderer (in fairness – there is one instance of a murderous couple included in this number). This is pattern persists for Marsh throughout her career. We may again ignore the 1980s where the numbers are insufficient for any valid conclusion to be drawn.

Interestingly, the average age of Marsh’s murderers tends to be slightly lower than their victims at 43, though again, making allowance for the margins for error in the estimation of their ages it might be safer to conclude they are in their lower 40s.

There is, however, no distinct pattern discernible in the deviations in the murderer’s age across the decades of Marsh’s career beyond a subtle increase as she herself ages. Perhaps, as she entered her 60s and 70s she felt that the energy necessary to conceive and be motivated to carry out a murder was within the compass of individuals somewhat older than she imagined when she was younger.

There is however, a resolutely middle class bias among her murderers. The plots thus retain the essential coziness of familiarity necessary for the intellectual detachment of a Golden Age puzzle. I therefore tend to find the examples where her murderers turn out to be working class more disturbing as if this is an uncomfortable reminder of class tensions that I would rather set aside in this slightly unreal fictional world.

If we sum up these analyses we conclude that the “average” Marsh mystery sees a middle class male victim in his late 40s being murdered by a middle class male in his early 40s. It is reassuring to find therefore, when one looks at the specifics, that there is no single example where this is actually the case, demonstrating, if such were necessary, that statistics does lie out there in the world of fiction beyond lies and damned lies. (I repeat here, however, my caveat that this is based on my own guesstimate of the ages of protagonists and others may have different views which could give lie to my conclusion above.)

Marsh has her murderers commit their crimes, as one would hope, in a variety of ingenious ways, including luring their victims into boiling mud pools, but they can be classified under a number of broad headings.

As might be expected, given the overwhelming majority of her murderers are male and younger (so it might be assumed probably also fitter) than their victims, their choice of methods derive from the advantage they might enjoy of physical strength with stabbings, bludgeonings with a variety of blunt instruments and stranglings feature most commonly. Poisoning is also favoured, which is typically supposed to be a woman’s method but in all but one case, it is in fact a man who uses poison. It is noticeable, however, that with only a single exception, the male poisoners are all at least the same age or older than their victims (and none is a young man) which suggests that Marsh pays attention to the likely physical aptitude of her murderer when selecting her method for them to employ in their crime.

It is also instructive to consider the relative popularity of different methods over time.

Poisonings are the most common type of murder in the 1930s. This no doubt reflects the relative ease with which quite deadly poisons, such as arsenic and cyanide could be obtained from a local chemist at the time provided the murderer could concoct a convincing reason for needing the poison and was willing to sign the register to record the purchase.

By the 1940s, stabbings had become the favoured method for despatching the victim while poison had fallen to fifth place in the choice of murder weapon. This decade also was one of two, the other being the 1970s, when Marsh’s invention stretched to more esoteric methods (it was now that she saw off one victim in boiling mud bath in New Zealand).

Stabbing remained the favoured method for Marsh through the 1950s but this decade saw this method challenged for supremacy by bludgeoning the victim to death.

This trend continued into the 1960s with bludgeoning the victim now becoming the preferred method in the majority of cases. This is the only decade when a single method was so predominant.

By the 1970s, Marsh favoured strangling as the murderer’s chosen method but we see a second flowering of the more obscure methods for killing the victim – staging a riding accident – reflecting a desire to go beyond the conventional approach.

Drilling down to the use of specific methods we see a number of patterns emerge which may be explained by contemporary events.

Shootings occurred only in the 1930s. Thereafter, Marsh never used this method. This almost certainly reflects the changing attitudes to gun ownership – especially handgun ownership – over time. In the years after the First World War, there were undoubtedly a large number of pistols in private hands which were souvenirs, or trophies, from that conflict. Thus, people would be more familiar with and accepting of the presence of guns in households, in particular where a man in the house had fought in the war than would be the case in later decades.

Murders by poison also show a consistent downward trend over time. While at the outset of Marsh’s writing career, the access to, and use of poison, for the purposes of pest control was regulated, it was nevertheless quite definitely in the hands of the householder to deal with such pests as might infest the property. The advent of small businesses to address the market for this service coinciding with increasingly strict regulation of access to such poisons, no doubt made it more difficult for a would-be murderer to obtain the necessary materials to poison their victim and so Marsh resorted to this method less over time.

Conversely, strangling as a method showed a consistent increase in use by Marsh as time went on. This method, of course, does not rely on the use of a weapon, such as a gun or poison, to which access is difficult or requires explanation. Manual strangulation or using a rope or cord presents the murderer with no difficulties in the acquisition and safe disposal of the weapon (if indeed a weapon is even used) when increasing sophistication of police forensics (Marsh habitually depicted her detective Alleyn supported by a forensic team – Bailey the fingerprint expert and photographer Thompson both of whom enjoyed careers in excess of forty years at the rank of Detective Sergeant) made other weapons more susceptible of detection.

Stabbings also show a generally upward trend save for a complete absence of their use during the 1960s. There is, in the real world, increasing concern about knife crime, and the ease with which knives of lethal capacity, in terms of length and sharpness, can be purchased no doubt facilitates this equally in the fictional world Marsh creates. There has never been a shortage of carving knives in the English home to enable the Sunday roast to be carved or the unfortunate victim to be despatched.

The peak of Marsh’s use of death by blunt instrument (again a type of weapon that is frequently found conveniently to hand in one shape or another and requires little advance planning to both acquire and to be disposed of) is in the 1960s. Its prevalence explains the dramatic drop in stabbings with which it coincides. Thereafter, it falls from popularity, perhaps being too mundane to sustain interest in an increasingly demanding audience seeking the sensational.

As befits one of the four Queens of Crime, Marsh sets her crimes in London and in rural English settings. The country houses are, as might be expected, given her predominantly middle class murders, perhaps less grand than those to which the Sayers and Allingham took their upper class amateur detectives.

Marsh must also contrive reasons for her Scotland Yard detective to be called in by the local police when the crime takes place outside London.

Given her roots in New Zealand, it is unsurprising that, with isolated exceptions, her overseas crimes take place in her home country. This involves further ingenuity in coming up with reasons why Alleyn is transplanted from his London base. A wartime diversion to pursue possible spies and other fifth columnists sabotaging the war effort thousands of miles from the fighting in the Pacific provides one such, more than slightly implausible, justification as do secondments to international operations against drug cartels, albeit that these seem to employ somewhat small scale and unfeasibly amateurish modes of operation.

Perhaps most notably, Marsh sets a disproportionate number of her murders in theatre settings. Her own knowledge of that world was extensive – her elevation to “Damehood” as she called it was for her efforts in that field rather than for her literary endeavours – and her books provide a vivid and, it must be assumed, accurate portrayal of backstage life in a theatre company with all the attendant tensions and rivalries.

This certainly accounts for the emergence of employment relationships as the most common between murderer and victim. Whether relationships are of employer and employee, or co-worker, the heightened emotions and charged atmosphere of working on the stage provides a plausible scenario in which the murder may take place.
As might be expected, in common with the real world, the next most common relationships are within the family, though the number of spouses who murder is perhaps less than the norm, but then if fiction were to conform too closely to fact there would be a significantly reduced puzzle element to detective fiction whether by Marsh or any other writer.

As has already been noted, Marsh seems to return to the trope of the drug world with perhaps greater frequency – approaching 10% of all cases – than might be expected in the Golden Age detective fiction genre and while this may be a factor in a high proportion of real world murders it is somewhat incongruous in the nice middle class world about which she writes.

I feel bound to conclude this studiously statistically based analysis of Marsh’s oeuvre with what I must confess are strictly anecdotally evidence based observations. I fear that whatever level of fame or notoriety I might ever achieve, nothing would induce me to sit (or indeed pose in any other way) for a portrait by Alleyn’s artist wife Agatha Troy and, similarly, notwithstanding my severe limitations in the thespian department, I would be equally reluctant to accept a role in any production staged at the Dolphin Theatre on the Southbank in London.