Our Environment in Miniature: Dust and the Early Twentieth-Century Forensic Imagination

Abstract

This article explores the articulation of the crime scene as a distinct space of theory and practice in the early twentieth century. In particular it focuses on the evidentiary hopes invested in what would at first seem an unpromising forensic object: dust. Ubiquitous and, to the uninitiated, characterless, dust nevertheless featured as an exemplary object of cutting-edge forensic analysis in two contemporary domains: writings of criminologists and works of detective fiction. The article considers how in these texts dust came to mark the furthest reach of a new forensic capacity they were promoting, one that drew freely upon the imagination to invest crime scene traces with meaning.

We are, allegedly, living in a new era of forensic investigation. Since the introduction of DNA profiling in the mid-1980s, the forensic terrain has been reshaped, with new iconography (spectral images of white-suited, anonymous crime scene investigators); new challenges (the prevention of material contamination and degradation); and a new set of spaces, especially the highly disciplined crime scene and its promised harvest of bio-trace evidence. These developments have not gone unnoticed. They feature in a burgeoning scholarly literature, which, in exploring debates ranging from population genetics and abstruse probability theory to the negotiation of protocols for retrieving, storing, analyzing, and presenting trace matter as evidence, has drawn attention to the complexities of securing DNA profiling as a viable forensic technology.¹ Forensics in this self-consciously novel cast has also entrenched itself in the public imagination and has been showcased on highly rated television shows such as CSI: Crime Scene Investigation and its legion of spinoffs, in best-selling crime novels, and in our daily newspapers.²

Yet attention to our forensic present has not been matched by historical analysis, particularly for the twentieth century, and this neglect comes at a cost: in the shadow of the recent, undeniably spectacular advances in forensic techniques, prior practices are often assumed to be relics of a bygone age, discontinuous from—and thus uninteresting to—the world we now inhabit.³ Indeed, the current embrace of “cold case review” operates on and reinforces a marginalized view of earlier regimes of forensic theory and practice, which, if entertained at all, tend to be dismissed as grounded in “untested assumptions and semi-informed guesswork.”⁴

This article’s aim is to open up a space in which to think historically about our understanding, and imagining, of contemporary forensic investigation. It does so by taking one of the best-recognized features of today’s forensic landscape—the crime scene—and exploring its articulation at the turn of the last century, both in an emergent criminalistic literature and in the flourishing contemporary genre of detective fiction. It was in these texts that practitioners and public alike were instructed about the enabling conditions for a new model of crime scene investigation: first, the suspension of the scene in time and space, with the aim of constructing a matrix in which evidentiary objects and their physical context could be subjected to a sequential and differentiated set of practices undisturbed by decay, degradation, or contamination; second, its methodical excavation for physical evidence.

Both conditions featured prominently in the writings of two pioneering theorists of the crime scene: the Austrian jurist Hans Gross (1847–1915) and the French criminalist Edmond Locard (1877–1966). Gross’s Handbuch für Untersuchungsrichter als System der Kriminalistik (first published in 1893, with an English translation following in 1906), is widely regarded by subsequent forensic practitioners as the first systematic practical manual for criminal investigation. Locard, founder of Lyon’s innovative police laboratory (1910), built on Gross’s pathbreaking work, especially by elaborating on the ways in which modern laboratory methods and technologies could be deployed to make sense of the objects identified at the crime scene. For Gross and Locard, crime scene investigation centered on the disciplined search for minute, and ostensibly insignificant, trace evidence: blood, hair, fibers, and, most evocatively, what they called “dust.” Ubiquitous and, to the uninitiated, characterless, dust represented the exemplary object of a modern forensic analytic. It was, for Gross, “our environment or surroundings in miniature”; for Locard, “the microscopic debris that cover our clothes and bodies are the mute witnesses, sure and faithful, of all our movements and of all our encounters.”⁵

Though Gross and especially Locard sought to secure dust as a practical forensic object, their discussions were at times unabashedly speculative in tone. For them dust symbolized the furthest reach of the new forensic capacity that they were championing, one that—like the mixed representational sources underpinning our own understanding of a world of infinitesimal trace evidence—could legitimately draw upon contemporaneous imaginative discourses that invested dust with meaning.⁶ Locard, for example, in addition to producing technical treatises on criminal investigation, wrote a book explicitly devoted to the intersection of detective fact and fiction, in which he freely admits to borrowing “from the adventures of Sherlock the initial idea of studying clothing dust and dirt stains.”⁷

Dust’s place in the making of the modern crime scene, I will argue, was indeed suspended in interesting (and productive) ways between fact and fiction, its status in practitioner manuals supplemented by its exploitation as an evidentiary object in contemporary detective stories. To follow this path, however, I will focus not on Conan Doyle’s celebrated creation, but on a once popular but now largely forgotten successor: Richard Austin Free-man’s (1862–1943) character, Dr. John Evelyn Thorndyke. It was in the Thorndyke stories that dust enjoyed its most systematic, and unencumbered, exposition and, explicitly positioned at the intersection of public education and public entertainment, brought to the attention of a wide audience the powers and possibilities of modern crime scene investigation.

Crime Scenes Before “Crime Scene Investigation”

Of course, all crimes take place in a definite space and time, and consequently criminal investigations past and present are rooted in a specific site. But it was only at the turn of the last century that the “crime scene” as a distinct analytical space, bounded conceptually and operationally by explicit rules of practice, and recognized as such by forensic investigators and the broader public alike, became the object of sustained consideration.

In the English context, there were few if any systematic manuals on criminal investigation for police practitioners produced in the nineteenth century.⁸ It was not in police guides but in the well-established medico-legal literature that the investigation of criminal acts received its most complete treatment, but this too was of a limited nature, in no small part due to its target readership: medical practitioners who, during the course of their everyday activities, might be called upon to assist legal authorities in the event of a crime against a person. In the classic case of suspected homicide, practitioners were given guidance about what to do when called upon to view a body where it was found. In his 1844 manual Principles of Forensic Medicine, the King’s College professor of forensic medicine William Guy prefaced his “brief directions” for observing and collecting facts related to persons found dead by drawing attention to the distinction between common and skilled witnesses. When approaching a dead body, a medical observer combined both of these functions, he explained, but it was only with respect to his investigation of the corpse that he acted in a skilled capacity. If called to the place where a body lay, Guy explained, the medical man “must of necessity observe many things connected with the body itself—the position in which it is placed, and the objects by which it is surrounded—which might just as well be observed and stated in evidence by any other person.” This contextual observation, a matter of “common” witnessing, stood in stark contrast to his duties with respect to the postmortem inspection of the corpse, which “can be made by himself alone.”⁹

At the crime scene, then, and in explicit contrast to his role at the postmortem slab, the medical man acted like an ordinary observer. Any difference, Guy continued, derived not from access to a specialized set of skills but from his putative qualities of mental refinement: “The medical man is not only one of the first witnesses of these facts; he is also in most cases by far the best educated and most intelligent witness.” It was on this basis that Guy exhorted the medical man to be “alive to all that is passing around him, that no object, however trifling, which may possibly throw light on the cause of death, may be overlooked.”¹⁰

In Guy’s vision, then, the exhortation to keen observation of the environment surrounding the body was based on the observer’s general intellectual assets rather than on mastery of a distinct method. Indeed, Guy explicitly refrained from providing rules to guide the medical man at the crime scene: “Each man’s own judgment and foresight must prompt the particular points to be observed in individual instances.”¹¹ This is not to say that the environment within which the body lay was to be ignored. Guy advised that the medical man’s general survey should be accompanied by attention to conditions such as temperature, moisture and ventilation, for these were variables that needed to be factored into the investigator’s core concern: determination of time and cause of death. Postmortem signs that might assist in this endeavor—body temperature, the presence of rigor mortis or lividity, degree of putrefaction, and the like—were contingent on such environmental variables, and, without a reliable record of them, conclusions drawn from the mortuary slab were prone to error. However, in contrast to Gross, these instructions were not aimed at using the physical space of the crime scene to reconstruct the circumstances by which a crime had been committed, but rather as supplements to the centerpiece of what I have elsewhere described as a traditional, body-centered forensics: the postmortem.¹²

This body-centered orientation in murder investigations persisted over the course of the century, though an increasing sophistication of the interplay between corpse and context is discernible. Charles Tidy’s 1882 Legal Medicine is a case in point. In a lengthy section on signs of death, the London Hospital’s professor of forensic medicine supplemented his discussion of the classic topics of rigor mortis and lividity with a consideration of the further deductions that were possible from these postmortem signs if the investigator took careful note of the “position and attitude of the corpse.” This could, for example, yield important information as to whether or not death had occurred at the spot where the body was discovered: if a corpse were found

fitting itself (as it were) to the surface on which it rests, the muscles of the buttocks or of other parts being flattened at the points of pressure, the probability is that the death occurred at the precise spot where the corpse is found. Supposing, however, there had been any interference with the body after death, such interference, it is next to certain, must have taken place before post-mortem rigidity set in.¹³

Despite such elaborations, late nineteenth-century treatises retained a focus on questions of the body: on the way the crime scene might yield clues about the cause of death and identity of the corpse. Analysis of the crime scene for the purpose of reconstructing the events leading up to the crime were not isolated as a special consideration requiring a specific set of skills or sensibility. As late as 1910, the Scottish medical jurist John Glaister Sr. was maintaining a lack of interest in crime scene investigation as a matter of medical concern: medical examiners, he wrote, did not need to extend their observations to matters such as clothing, “as that is the duty of the police.”¹⁴ It was the postmortem interpretation of the body, in other words, that was the primary concern of forensic expertise.

Grossian CSI and Locard’s Dust

Hans Gross was an Austrian criminal jurist and examining magistrate, who as Professor of Criminology established the University of Graz’s Institute of Criminology. In 1893 he published his influential Handbook, which is justly regarded as the first attempt to systematize the methods of crime investigation. Though less celebrated by historians than are other criminalist pioneers like Alphonse Bertillon, Gross’s widely translated and multi-edition text is arguably the progenitor of what we now recognize—on our TV screens and in our newspapers—as “CSI.”¹⁵

The lynchpin of Grossian CSI was the “Investigating Officer,” whose duty it was to transform the place where a crime had occurred from what Guy had described as the domain of “common” observation (as opposed to “skilled” mortuary-based observation) into one bounded by a distinctive set of analytical practices. This transformation was to be achieved through labor: emotional, spatial, and observational. The opening lines of his core section “What to Do at the Scene of Offence” underscores the first element of this labor: “On arrival at the scene of the crime,” Gross insisted, “the first duty is to preserve an absolute calm. With it everything is won, without it everything is compromised.” This regime of calm was directed in the first instance inwards: “Man indeed is naturally the victim of excitement,” Gross explained, “and in the presence of an important event can find no better way to control his agitation than by issuing orders wholesale, altering them, and at all hazards making things hum.”¹⁶ Resisting such natural impulses thus served as the foundational distinction of a crime scene officer. Internal calm was then to be radiated outward, by preserving as completely as possible the “existing vestiges of the crime.” This was achieved by fixing the crime scene as a spatio-temporal entity: “The exclusion of everything happening after the moment when the crime was committed,” he explained, “is a very special task for the Investigating Officer.”¹⁷ This had several components: for example, marking off a perimeter zone, preventing unauthorized access, and shielding objects within the zone from contact with forces that might degrade or contaminate them.

One of the prime sources of degradation was the undisciplined officer himself, who was susceptible to a further “natural impulse”—“to immediately touch any object of apparent significance, as e.g., an object left on the scene of the crime by the criminal.”¹⁸ Seeing beyond “apparent significance” and resisting its allure was another mark of distinctive expertise, restraint following from an understanding of the importance of seemingly trivial objects and relationships. The trained investigating officer approached the crime scene as an open-ended puzzle: “Everything may be of importance and nothing too small or insignificant to have a decisive bearing upon the case. The situation of an object an inch or two to left or right, to front or back, a little dust, a splash of dirt easy to efface, may all turn out to be of the first importance.”¹⁹

This indeterminate quality of objects and their interrelations encountered at the crime scene necessitated a further gesture of suspension, that won by strict adherence to the investigating officer’s “golden and inviolable rule”: “Never alter the position of, pick up, or even touch any object before it has been minutely described in the report.” Meticulous note-taking was at once the outcome of discipline and its guarantor. The investigator who recorded rather than touched secured a pristine crime scene for future analysis and confirmed both his physical and cognitive self restraint, his capacity to defer engagement with the world of immediate appearance in order to preserve one of as yet unseen, fragile traces and interrelationships. This was a world lost to the undisciplined, who take hold of and move crime scene objects, and only afterwards recognize “that the object in itself signifies very little but that everything depends on its position—which can no longer be fixed.”²⁰

Gross’s conception thus depended on a new expert imbued with specific cognitive and behavioral qualities. But the accomplishments of the investigating officer—his capacity to preserve the crime scene in space and time—were merely the first-order requirement. Once captured on record and carefully harvested, the “vestiges” of crime could only yield their secrets in a further disciplined domain: the crime laboratory. It is beyond the scope of this article to discuss in detail the crime lab as a technical and administrative space or to chart its institutional history. Instead, I limit myself to the observation that its status as a new domain of expertise and experts existed alongside—and in potential tension with—the traditional figure of the skilled medical witness at the mortuary slab. In the work of Gross, pathology is displaced, literally in the sense that it occupies a tiny fragment of his text, but also figuratively, in that the corpse is relegated to the realm of the immediate and obvious gross appearance, a distraction from the core work of scene investigation—trace analysis. Accordingly, the microscope emerges as the material counterpart to the heroics of the investigating officer, as an instrument that enables what appears as ordinary and insignificant to trump the corpse as the modern investigator’s core object. Microscopy takes pride of place in Gross’s text, with discussions of its uses in analyzing hair, fibers, blood, and other trace matter supplemented by examples drawn from his extensive case file. Dust forms part of this extended discussion, and though it is not given more space than any other substance, its role in stimulating an emergent forensic imagination is evident.

Dust features in Gross’s text as an exemplary object of crime scene investigation. To the uninitiated, dust is at best meaningless, at worst a barrier to meaning, an interfering layer to be wiped away in order to reveal the desired object lying beneath. But to the properly trained analyst, dust is every bit as significant as the things it covers. This is because dust is the eroded vestige of the more easily apprehended world of normal-scaled matter—“our environment or surroundings in miniature.”²¹ By identifying the qualitative features of any particle of dust found on crime scene objects, the investigator generated potentially vital evidence of the physical interaction between it and the object on which it had come to rest.²² This capacity of dust to bear witness to the environment from which it derived opened up a new world of trace linkages:

The dust of the desert will contain little besides pulverised earth, sand, and small particles of plants; the dust of a ball-room, crowded with people, will in great measure proceed from the fibres from which the clothes of the dancers are woven; the dust of a smith’s shop will be for the most part composed of pulverised metal; and that upon the books of a study nothing but the reunion of the particles of earth carried in on the boots of the master of the house and the servants with very tiny particles of paper. Examining more closely, we find that the coat of a locksmith contains a different kind of dust to that on the coat of a miller: that accumulated in the pocket of a school-boy is essentially different from that in the pocket of a chemist.²³

The rich harvest reaped from dust, moreover, reconfirmed Gross’s exhortation for a set of practices and sensibilities that looked beyond the obvious sources of evidence: “There is little probability of finding anything of importance if the attention be confined to safes, almirahs, beds, boxes, stoves, or chimneys,” Gross warned. The investigator would do better to consider the lowly pocket, which “tells us from its composition the whole history of a person during the time he has worn the garment.”²⁴

If Gross can be considered the founder of what we now think of as CSI, it was Edmond Locard who put dust at its center. Best known for his “exchange principle” with its much cited (though, in strict terms, apocryphal) aphorism, “every contact leaves a trace,” Locard was also a pioneer in the application of lab techniques to criminal investigation. In 1910, after studying medicine and law at the University of Lyon, and working with the criminologist Alexandre Lacassagne, he persuaded the local authorities to establish Europe’s first police laboratory, with him in charge. This was to be the base for Locard’s pathbreaking forensic work, which spanned a full half century and included heralded breakthroughs in such diverse fields as graphology, serology, and poroscopy. His first substantial treatise on criminalistic practice, L’enquête criminelle et les méthodes scientifiques, was published in 1920.²⁵ Here and in subsequent texts Locard established modern, lab-based police investigation as dependent on a combination of observational virtuosity and analytical precision rooted in a disciplined deployment of the imagination. Nowhere was this more evident than in his approach to dust.

Locard’s initial English-language reflections on dust’s analytical promise appeared in the London-based Police Journal in 1928. These were extended two years later in a series of articles entitled “The Analysis of Dust Traces” and carried by the American Journal of Police Science. In the first of these Locard began with an expression of surprise that it was only recently that investigators had conceived the simple idea of collecting dust from garments and other surface crime scene objects as “evidence of the objects rubbed against, and the contacts which a suspected person may have undergone. For the microscopic debris that cover our clothes and bodies,” he continued, “are the mute witnesses, sure and faithful, of all our movements and of all our encounters.”²⁶ Locard named two inspirations for his recognition of the forensic potential of dust: one was Hans Gross, whom Locard credited as the first author to provide substantive accounts of dust analysis in actual police investigations. “Next to this master,” he continued,

one should not be surprised to find the name of a popular novelist … . I hold that a police expert, or an examining magistrate, would not find it a waste of his time to read Doyle’s novels. For, in the adventures of Sherlock Holmes, the detective is repeatedly asked to diagnose the origin of a speck of mud, which is nothing but moist dust.

“I must confess,” he continued, “that if, in the police laboratory of Lyon, we are interested in any unusual way in this problem of dust, it is because of having absorbed the ideas found in Gross and in Conan Doyle.”²⁷

Two features of dust were central to its forensic significance. First was its ubiquity: “There is not a single object that is not covered with it, since, from the moment that one removes a layer of deposited dust, new dust immediately begins to fall on the places just wiped clean.” Second was its capacity to retain in qualitative form the morphology of its originary source. Locard defined dust as “an accumulation of debris” from any organic or inorganic body “in a state of pulverization.”²⁸ Yet pulverization did not obliterate all qualitative vestige of the object from which it originated. To illustrate dust’s surprising resilience, he invited his reader to consider a most unlikely evidentiary source: the body—and in particular the wings—of a dead butterfly:

Its body rapidly decomposes, falling into dust. The greater portion of its elements (those which are putrifiable) undergo a chemical evolution, through which one is later unable to determine their origin. On the other hand, certain other imperishable elements become mechanically crushed without chemical alteration, and their minute debris are still recognizable, with the right technique and adequate equipment. For example, the dust originating from the wings of butterflies can be determined, whereas the digestive organs undergo alterations which radically transform them. As a result of this knowledge we may state that dust preserves sufficient distinctive characters, so that one is able, almost invariably, to identify its origin.²⁹

The analytical promise of dust depended on a modification of Grossian crime scene technique. Gross had recommended placing a dust-laden object in a bag and beating it, but this in Locard’s view negated the potential value of mapping its pattern of distribution over the object in question: “The distribution of the dust,” he urged, “may possess an interest at least equal to that of its final identification.”³⁰ In order to capture this spatial dimension he outlined a strict regime of collection and recording, in which dust from each of the “interesting zones” was first photographed and, once harvested, was isolated in packets numbered to correspond with a card-index record.³¹ This painstaking work was facilitated by instrumental innovations, most notably a purpose-built vacuum cleaner to extract dust not visible to the naked eye.

Locard’s approach aligned the crime scene with practices associated with a range of contemporaneous field sciences, including geology, ecology, and especially archaeology. Most obviously, his concern with dust distribution drew on the importance of interpreting layers of matter, and therefore necessitated an “orderly method” of excavation and preservation. When investigating shoes, for example, “successive layers may be found under the sole of the shoe, each of which has its own significance.” He cited one case in which a layer of flour dust between two of earth provided evidence of entry into a mill. “In such circumstances,” he observed, “the removal of the dirt en masse would destroy all possibility of a stratigraphic study, which could be made only by taking one layer at a time.” In such instances he suggested drilling “a perpendicular incision into the shoe to obtain a good view of the respective strata.”³²

The overlap between Locardian crime scene excavation and contemporary archaeological practice is worth further consideration. In the latter decades of the nineteenth century, a new generation of archaeologists, led on the continent by Giuseppe Fiorelli in Italy, Alexander Conze in Austria, and Ernst Curtius in Germany, and in England by Augustus Henry Lane Fox Pitt-Rivers and William Matthew Flinders Petrie, were forging a program of scientific excavation based on a number of characteristics whose affinity with crime scene investigation is evident.³³ Most obvious was the emphasis on the need to produce an exhaustive audit of a site irrespective of any prior hierarchy of value assigned to the objects that lay within any field. This new sensibility demanded, and enacted, a set of disciplines based on suspension of preconceived judgment as to what was worthy of note and, consequently, a willingness to embrace the tedium of “total recording.”

Pitt-Rivers’s celebrated fieldwork on his Dorset estate, chronicled in his multivolume Excavations in Cranborne Chase, exemplified this approach. In introducing his enterprise, he alerted readers that his methods and his account of them were of a piece, and that both necessitated an expositional style at odds with conventional narratives:

It will, perhaps, be thought by some that I have recorded the excavations of this village and the finds that have been made in it with unnecessary fulness, and I am aware that I have done it in greater detail than has been customary, but my experience as an excavator has led me to think that investigations of this nature are not generally sufficiently searching and that much valuable evidence is lost by omitting to record them carefully.³⁴

As a rule, he explained, excavators limited their accounts to “only those things which appear to them important at the time,” but as a dynamic discipline in which fresh discoveries—physical and/or perspectival—were continuously generated, such limited accounts stifled productive reengagement: “On turning back to old accounts in search of evidence, the points which would have been most valuable have been passed over from being thought uninteresting at the time. Every detail should, therefore, be recorded in the manner most conducive to the facility of reference.”³⁵

The new archaeology, then, defined itself by its concern with “trivial details” and their meticulous recording: it was by careful attention to “odds and ends that have, no doubt, been thrown away by their owners as rubbish,” that archaeology produced knowledge of real value.³⁶ The emphasis on the value of everyday objects and their relations in space and time, and their systematic excavation and recording was in these texts set in stark opposition to the unscientific and destructive practices of the “treasure hunter.” Petrie’s 1904 Methods and Aims in Archaeology stands as a model, moralizing articulation of this contrast, in which traditional practitioners are criticized as being “still attracted by pretty things, rather than by real knowledge.”³⁷ In their quest for buried treasure, these old-style diggers fetishized objects of superficial value and in so doing overlooked—and indeed destroyed—the more complex analytical possibilities of an excavation site. Achieving knowledge at this level, Petrie insisted, entailed

the power of conserving material and information; of observing all that can be gleaned; of noticing trifling details which may imply a great deal else; of acquiring and building up a mental picture; of fitting everything into place, and not losing or missing any possible clues; all this is the soul of the work, and without it excavating is mere dumb plodding.³⁸

As with the systematic investigation of the crime scene, all this labor would be for naught without submission to a further discipline of the field: “Recording,” Petrie intoned, “is the absolute dividing line between plundering and scientific work.”³⁹

This attention to unremarkable objects as evidentiary traces of some broader set of events that had previously transpired thus inter-articulates archaeology and crime scene investigation at the level of sensibility and of practice. In turn, this emphasis on the value of the “incidental” is part of a more fundamental shift in the interpretive methodologies characterizing a range of nineteenth-century historically based disciplines—including history itself. In the geology of Charles Lyell, the paleontology of Georges Cuvier, the evolutionary biology of Charles Darwin, and the history of Johann Gustav Droysen, historical narrative was properly anchored in unintentional material sources rather than in those constructed (physically or verbally) for explanatory purposes.⁴⁰ Each of these depended on a node of related disciplines—interpretive and gestural restraint, interpretive openness, representational fidelity—that enabled commonplace matter to testify more eloquently than more obvious evidential “treasure.” For Locard, the connection was clear: “The detective, one might say, reconstructs the culprit’s identity from the traces he leaves behind, just as the paleontologist reconstitutes a fossil from its fragments.”⁴¹

In the third installment of his “Analysis of Dust Traces” Locard reviews twenty-two cases of criminal investigation centered on dust, roughly half of which involved homicide. One is worth briefly reviewing, as it epitomizes the way dust analysis displaced what could be characterized as the “plundering” approach to crime scenes represented by a mortuary-centered focus on the body removed (conceptually and physically) from the crime scene. In 1925 a male body was found beside a canal next to a gasworks, near which was also a stone yard containing huts that provided workmen with shelter. The thighs and chest were covered with a grayish-white dust; a darker substance coated the hands and feet; the ear canal, scalp, and fingernails contained further distinctive debris. Laboratory analysis determined a peculiar combination of organic and inorganic sources of this dust, which was subsequently found replicated in the stone yard. Of particular significance was the discovery of a bag of coal in one of the huts, the particles of which matched the dust distributed across the corpse’s thighs and chest. This match corroborated the account given by the case’s preliminary suspect, who claimed to have used an old coal bag to cover the corpse that he had chanced to come across. In this way, attention to the surface coating of the corpse and its contextual mapping—the transformation, in effect, of the corpse into a “crime scene” laden with analyzable trace evidence—provided the key to the case’s successful resolution.⁴²

Fictions of Dust

These early dust theorists recognized that they were engaged in a speculative venture, one that, in comparison to those carried out with more traditional methods, might hint at desperation. “No doubt examinations of this sort never guarantee certain success,” Gross acknowledged, “but they should not for all that be classed among those ‘forlorn hopes’ employed when we are at our wit’s end to know what to do.”⁴³ Here Gross identifies two core challenges facing dust analysis in real time: the practical difficulties involved in analytical differentiation, and the resistance on the part of police officials borne out of skepticism about its ultimate evidentiary value. Edmond Bayle, founder of the Paris crime lab at the Sûreté and himself a champion of trace analysis, pointed to this tension in his assessment of the state of trace-oriented forensics after three decades of work: “Truth lies always between theory which moves too fast, and routine which moves too slowly.”⁴⁴

There was, however, another arena—that of the detective story—in which dust analysis was projected as the cutting edge of forensic investigation. The interpenetration of detective fiction with real-world methods was a self-conscious feature of turn-of-the-century criminalist texts. As noted earlier, Locard was unabashed in acknowledging fictional counterparts as an imaginative springboard for his program of scientific policing, nowhere more explicitly than in his 1924 Policiers de roman et policies de laboratoire, the first half of which is devoted to the exploits of Edgar Allen Poe’s C. Auguste Dupin,Émile Gaboriau’s Monsieur Lecoq, and Arthur Conan Doyle’s Sherlock Holmes. Locard’s purpose is clear: to use these most publicly recognizable crime fighters to stimulate a practical program of reform, by “drawing attention to what the police can do and what they might do if they were to break out of their habitual routines.”⁴⁵ Their power, in Locard’s view, derives from the contemporary public’s “passion for the art of the detective,” which he compares to the influence of earlier literary genres: just as Johann Wolfgang von Goethe and François-René de Chateaubriand spawned a generation of neurasthenics, and Victor Hugo and Alfred de Musset made the romantic spirit bloom, so too did Locard’s trio ingrain for their public the essential lesson of scientific policing: that no matter how cunning, the criminal “always leaves behind involuntary signs of his movements, and that this testimony is the only kind that never lies.”⁴⁶

Though Locard celebrates the logical acumen of Dupin’s and Lecoq’s enthusiastic approaches to crime scene investigation, he reserves his fullest praise for Sherlock Holmes. By drawing together techniques that were previously only articulated as separate domains of knowledge and practice (and indeed at times inventing new ones), Holmes created an integrated language of police science, a feat rivaled in Locard’s estimation only by Gross himself. In his exploration of Holmes’s genius, Locard devotes particular attention to the elements of CSI that I have outlined thus far. This distinguished Holmes from Dupin, whom Locard views as an armchair logician content to work with information gathered secondhand. Gaboriau’s Lecoq improves on Poe’s creation, in that his adventures feature an added dimension—“the study of the technique of traces, the analysis of the crime conducted at the scene.”⁴⁷

But Holmes is the unsurpassed master of trace-centered police science, a judgment that Locard admiringly illustrates through classic examples of Holmesian CSI. The “Boscombe Valley Mystery” crime scene, for example, showcases both virtuoso technique and its potential to drive practical reform—Holmes’s lament about the “herd of buffalos” that had defaced the crime scene, Locard observes, should “serve as an epigraph to every manual addressed to police agents.”⁴⁸ And of course Locard is quick to highlight Holmes’s credentials as a forerunner of modern dust analysis, admiring his identification of the Trichinopoly cigar ash at the murder scene in A Study in Scarlet and of the Wigmore Street post office’s distinctive red clay in The Sign of Four.

By pairing his appreciative survey of policiers de roman with one featuring those of the laboratoire, Locard underscores—and turns to his own purposes—the blurred boundary between detective fiction and the methods that he and Gross promoted. As numerous scholars have recently observed, this self-conscious imbrication of detective fiction and fact was by no means limited to Locard. The literary critic Ronald Thomas, in his influential Detective Fiction and the Rise of Forensic Science, notes that pioneering investigators commonly cited literary inspirations for their work, seeing these as useful vehicles for communicating contemporary developments in the field. Thomas also suggests that the medium in which these stories were often projected contributed to this productive intertextuality—the Holmes stories, for example, appeared in the Strand magazine alongside articles about real police cases and reports of related scientific innovations, thereby creating “an indistinct boundary between truth and fantasy, imaginative literature and journalistic reportage.”⁴⁹ Melissa Littlefield’s analysis of the “edutainment” value of early twentieth-century detective fiction reaches a similar conclusion: that these stories actively engaged debates about how modern forensic investigation should be conducted, serving, in effect, as “literary advertisements for the sciences they employed.”⁵⁰ The crime historian Haia Shpayer-Makov’s account of detective policing in Victorian and Edwardian England—the second half of which surveys representations of detectives in journals and newspapers, in novels and short stories, and in memoirs—also concludes that the fictional detective was an inescapable point of reference for his factual counterpart. In police memoirs, for example, Holmes is a constant (and largely infuriating) presence, with few such texts, even into the postwar era, failing to invoke him and his exploits.⁵¹

There is a further connection worth briefly making between recent scholarly analysis of detective fiction and the model of crime scene investigation that I am attributing to Gross and Locard. As Thomas and (more fully) Lawrence Frank have argued, detective fiction served as an important model for working out and illustrating the logic and practices of the historically grounded disciplines—geology, paleontology, evolutionary biology, archaeology—that grew to prominence in the nineteenth century and that were predicated on reconstructing a narrative of past events out of incomplete and unintentional physical traces.⁵² The focus on patient sifting, recording, and analysis of fragmentary evidence rather than on exegesis of traditional, intent-laden sources; the virtues of systematic, dispassionate, and neutral evaluation of incidental trace material irrespective of its ostensible value; the faith in the evidential worth of mute material witnesses in this sense embed crime scene work—whether in criminalist manuals or in detective fiction—within a deeper contemporary epistemic matrix.

For a number of reasons, then, a discussion of crime fiction is appropriate and even necessary for my account of the rise of trace-centered crime scene investigation as articulated at the turn of the twentieth century. Space permitting, this discussion would include a comparative analysis of how a range of characters (including the canonical trio of Dupin, Lecoq, and Holmes) interact with and help to articulate this space. Given present limitations, and my specific interest in dust as an exemplary object of a forensics of traces, however, I propose a different focus: a selection of cases featuring Richard Austin Freeman’s creation, Dr. John Evelyn Thorndyke.⁵³

In a career spanning three decades following his 1907 debut in The Red Thumb Mark, in which he featured in more than twenty novels and many more short stories, Thorndyke earned a reputation as “the scientific detective par excellence … [whose] power comes not from a superhuman intellect, but from specialised knowledge, technology and method.”⁵⁴ In eschewing Holmes’s often eccentric conclusions in favor of ones grounded in carefully delineated laboratory methods, Freeman was following an explicit pedagogic agenda with two principle aims: first, to instruct police officials on their proper duties in criminal investigations, and second, to educate the public about the powers of modern crime scene investigation. Freeman employed a range of devices in this effort. The best remembered of these is his formal innovation—the “inverted detective story”—which, by providing at the outset a detailed account of the crime and its perpetrator, shifted narrative emphasis from the traditional “whodunit” question to the “how,” and in so doing foregrounded the analytical techniques performed by the character.⁵⁵ Freeman also showcased the workings of crime scene investigation and its analysis of a world of minute trace evidence by inserting into the text photomicrographs that at once illustrate the story, enhance its scientific verisimilitude, and enable the reader to experience the regime of laboratory visuality that Freeman sought to promote (see figs. 1-2).⁵⁶

figure 1.

“Fluff from Key-Barrel, magnified 77 diameters.” From R. Austin Freeman, “The Stranger’s Latchkey,” in John Thorndyke’s Cases (London, 1909).

figure 2.

“The Sand from the Murdered Woman’s Pillow, magnified 25 diameters.” From R. Austin Freeman, “A Message from the Deep Sea,” in John Thorndyke’s Cases.

From the outset of Thorndyke’s career Freeman was explicit about the ultimate objective of such strategies. In the preface to his anthology of stories, published in 1909 and dedicated to his friend Frank Stanfield “in memory of many a pleasant evening spent with a microscope and camera,” Freeman explains his working principles:

I have been scrupulous in confining myself to authentic facts and practicable methods. The stories have, for the most part, a medico-legal motive, and the methods of solution described in them are similar to those employed in actual practice by medical jurists. The stories illustrate, in fact, the application to the detection of crime of the ordinary methods of scientific research. I may add that the experiments described have in all cases been performed by me, and that the micro-photographs are, of course, from the actual specimens.⁵⁷

As a self-anointed apostle of forensic modernity, Freeman reflected and amplified many of the core themes I have discussed thus far. He fully embraced Grossian discipline, for example, urging the need to preserve the crime scene in space and time: “When it is discovered that a murder has been committed,” Thorndyke declares at the conclusion of one of Thorndyke’s earliest published cases,

the scene of that murder should instantly become as the Palace of the Sleeping Beauty. Not a grain of dust should be moved, not a soul should be allowed to approach it, until the scientific observer has seen everything in situ and absolutely undisturbed. No tramplings of excited constables, no rummaging by detectives, no scrambling to and fro of bloodhounds.⁵⁸

As this striking quote suggests, moreover, dust looms large in the Thorndyke canon. The solution to the “Sleeping Beauty” murder centered on the identification of a fine powder, wrongly assumed to be everyday soap crystals by the police, as coral residue found only in the Eastern Mediterranean and ultimately linked to a local wholesaler who had recently processed a batch of Turkish sponges laden with this aquatic dust. This arcane resolution of what at first glance appeared a straightforward case of jealous rage was only possible because, by chance, Thorndyke had arrived at the murder scene ahead of the police, and had thus been able to enact his crime scene protocol unencumbered. The value of this disciplined approach, he pointedly observes, was a “lesson that the authorities still refuse to learn”:

Consider what would have happened in this case if we had arrived a few hours later. The corpse would have been in the mortuary, the bed rummaged and the sand scattered abroad … . There would not have been the vestige of a clue, and the deep sea would have uttered its message in vain.⁵⁹

In another story in the same collection, Thorndyke makes his first programmatic statement on the value of dust, when, in the wake of his successful identification of the constituent elements of “latchkey fluff,” he urges constant companion and Watsonian foil, Christopher Jervis, to make a study of this unpromising form of matter: “You will have, Jervis, to study the minute properties of dust and dirt. Their evidential value is immense.”⁶⁰ Over the course of his long and eventful career Thorndyke makes good on this portentous advice, as dust drives the plot of dozens of his cases, and serves multiple pedagogic purposes. I restrict myself to three: his demonstration of the practical, instrumental, and conceptual labor involved in excavating and analyzing crime scene dust; his elevation of dust over alternative, and more traditional, elements of forensic investigation, in particular the postmortem; and the place of dust in the public (and criminal) consciousness.

A good example of the archaeologically inflected nature of Thorndyke’s approach to dust appears early in his career, when in the 1912 short story “A Wastrel’s Romance” an elderly woman attending a party at a country estate was attacked and robbed whilst taking a stroll through the gardens. The victim provided the police with a generic physical description of her assailant and recalled that he had been in evening dress. A visit to the cloak room revealed that a man had left in a hurry shortly after the crime, that he had taken the wrong coat, that his coat was still on the peg, and that its pocket contained a tram ticket.

The police could do nothing with this information: in the words of the superintendent, the lady “has given us a description that would apply to fifty per cent of the middle-class men of the United Kingdom, and has shown us a coat without a single identifying mark of any kind on it, and expects us to lay our hands on the owner without a solitary clue to guide us. Now we are not sorcerers at the Yard; we’re only policemen.”⁶¹ Thorndyke, called to assist by the exasperated and overtly skeptical superintendent, agrees to take the coat for investigation. On being asked by his companion Jervis why he doesn’t start with the obvious—the tram ticket—Thorndyke explains that doing so risked the introduction of a potentially misleading form of evidence: “A man may take a tram anywhere, whereas the indoor dust on a man’s coat appertains mostly to a definite locality.”⁶² When Jervis presses him by observing that the information derived from dust is “excessively vague,” he gets a corrective lecture:

As I have often pointed out, the evidential value of dust is apt to be under-estimated. The naked-eye appearances—which are the normal appearances—are misleading. Gather the dust, say, from a table-top, and what have you? A fine powder of a characterless grey, just like any other dust from any other table-top. But, under the microscope, this grey powder is resolved into recognizable fragments of definite substances, which fragments may often be traced with certainty to the masses from which they have been detached.⁶³

Once in the lab, Thorndyke commences a methodical and laborious excavation of the coat, deploying an “ingenious” apparatus invented by his resourceful lab assistant, Nathaniel Polton: a vacuum cleaner with a specially adapted receiver into which a microscope slide could be inserted. Thorndyke proceeded to apply the nozzle of the instrument to different parts of the coat, inserting a fresh slide for each defined area vacuumed. This process resulted in half a dozen slides “charged with dust from different parts of the garment,” which on microscopic inspection revealed not only different and distinct dust entities—including wheat and rice starch, black pepper resin and pimento cells, traces of cocoa and turmeric, and graphite—but also the fact that while some of these substances were distributed over the entire coat, others were present only on certain parts. The potential significance of this finding, for Thorndyke, was clear: “We must locate those parts exactly and then consider what this special distribution means.”⁶⁴

What ensues is a reengagement with the coat and its differentiated dust, which mirrors Gross’s disciplined approach to crime scene recording and mapping, and indeed the insistence of Petrie and his contemporaries on spatialized recording at excavation sites.

He rapidly sketched out on a sheet of paper a rough diagram of the coat, marking each part with a distinctive letter, and then, taking a number of labelled slides, he wrote a single letter on each. The samples of dust taken on the slides could thus be easily referred to the exact spots whence they had been obtained. Once more we set to work with the microscope, making, now and again, an addition to our lists of discoveries, and, at the end of nearly an hour’s strenuous search, every slide had been examined and the lists compared.⁶⁵

The basic conclusion resulting from this meticulous mapping of the spatial relations of dust was clear even to Jervis: “‘Evidently,’ I said, ‘the particles that are all over the coat represent dust that is floating in the air of the place where the coat habitually hangs. The graphite has obviously been picked up from a seat and the cocoa and hops from some factories that the man passes frequently, though I don’t see why they are on the right side only.”’

Here Thorndyke takes over, overcoming the limits of Jervis’s analysis of space by introducing a further dimension:

“That is a question of time,” said Thorndyke, “and incidentally throws some light on our friend’s habits. Going from home, he passes the factories on his right; returning home, he passes them on his left, but they have then stopped work. However, the first group of substances is the more important as they indicate the locality of his dwelling—for he is clearly not a workman or factory employee. Now rice-starch, wheat-starch and a group of substances collectively designated ‘spices’ suggest a rice-mill, a flour-mill and a spice factory.”⁶⁶

Recourse to the post office directory yields only one location in London containing “the peculiar combination of factories necessary to produce the composite dust in which this coat has hung.”⁶⁷ Turning finally to the tram ticket left in the dusty coat, they find the name of this district printed as its destination.

Thorndyke’s refusal to focus his enquiry on obvious pieces of evidence in favor of the subtleties of dust in “A Wastrel’s Romance” resonates with the modern approach to scientific excavation—be it archaeological or criminalistic—that critiqued prior practices of evidentiary “treasure hunters” whose object fetish blinded them to the deeper meanings conveyed by the relations between ostensibly trivial trace matter. In the context of homicide investigation, the most obvious “treasure” was the corpse, and here I want to use a couple of Thorndyke stories to suggest how, like contemporary dust theorists, Freeman displaced the body as the narrative focal point. First it is worth pointing out that Freeman, toward the end of his career, provided a principled explanation for his approach:

A widely prevailing error is that a detective story needs to be highly sensational. It tends to be confused with the mere crime story, in which the incidents—tragic, horrible, even repulsive—form the actual theme, and the quality aimed at is horror—crude and pungent sensationalism. Here the writer’s object is to make the reader’s flesh creep; and since that reader has probably, by a course of similar reading, acquired a somewhat extreme degree of obtuseness, the violence of the means has to be progressively increased in proportion to the insensitiveness of the subject.⁶⁸

This public appetite for details of gory crimes had been fed in the early decades of the twentieth century by what I have described elsewhere as the cult of the “celebrity pathologist.”⁶⁹ Here, press reports of the discovery of a brutally murdered and dismembered corpse—often exhumed and in a state of advanced putrefaction—served as the opening scene of a well-recognized drama featuring the heroic labors of expert pathologists like Sir Bernard Spilsbury who, within the enclosed space of the mortuary, single-handedly reconstructed the details of the gruesome crime.

Like Gross’s and Locard’s dust collectors, Freeman positioned his hero as an alternative to body-centered detection. He did this in part by frustrating the generic expectations of celebrity pathology, and also by showing time and again how the trace evidence on and around the body was of more value than that derived from a medically driven postmortem investigation divorced from the analytical matrix of the crime scene.

An early Thorndyke story shows Freeman playing with the conventions of a corpse-centered forensics. “The Case of Oscar Brodski,” published in 1912 and commonly regarded as the first “inverted” detective story, contains a scene in which Thorndyke and the police inspector confront grim human remains in a mortuary:

As the inspector removed the tarpaulin, he glanced down on the corpse, lying limply on the stretcher and looking grotesquely horrible with its displaced head and distorted limbs. For fully a minute he remained silently stooping over the uncanny object.⁷⁰

Thorndyke then reaches into the “green bag” that is always with him at crime scenes and pulls out dissecting forceps. This gesture, seemingly the first stage of a postmortem sequence, prompts an objection from the attending policeman: “We’ve no authority to make a post mortem, you know.” This interjection—itself an element of a wider contemporary debate about the relative power of coroners, pathologists, and the police over suspect corpses, and which in a more conventional narrative would prompt a robust critique of the antiquated and unscientific system of English death investigation— leaves Thorndyke supremely unconcerned:

“No, of course not,” said Thorndyke. “I am merely going to look into the mouth.” With one pair of forceps he turned back the lip and, having scrutinized its inner surface, closely examined the teeth … . At length, very delicately, he picked out with his forceps some minute object from between two of the upper front teeth and held it in the focus of the lens.⁷¹

The object was a tuft of fabric, and, once retrieved, Thorndyke’s “postmortem” was at an end. The identification of this trace remnant, predictably, proved indispensible in solving the crime.

One of Freeman’s later full-length novels, the 1933 Dr Thorndyke Intervenes, presents the reader with a riotous medley of circumstances and events tailor-made for the intervention of the “celebrity pathologist”—a headless corpse and a pair of corpseless heads, an exhumation scene, and newspaper headlines trumpeting the latest “Horrible Discovery” that whipped the public into a frenzy and the police into increasingly desperate action. Thorndyke, as is continually noted by the anxious police inspector, seems not the least bit interested in the gruesome elements of the case. “I am not taking that head so calmly as you are,” the exasperated policeman exclaims in one such encounter.

It has been the bane of our lives at the Yard, with all the newspaper men shouting “unsolved mystery” and “another undetected murder” and asking perpetually what the police are doing. And it really was a mysterious affair. I have been surprised to notice how little interest you have taken in that head.⁷²

At another point in the story, Thorndyke comes face to face with the severed head, and his response is recorded with incredulity: “He could not have been less moved if it had been a wax-work head.”⁷³ Again, by following dust instead of body parts, Thorndyke prevails.

Thorndyke’s indifference to mutilated flesh leads me to my final theme: the way in which dust analysis features in his adventures as a matter intersecting expert, public, and criminal understanding. In their elevation of trace evidence, Gross and Locard had urged the advantages of such “mute witnesses” over their human counterparts. Yet trace evidence was itself recognized as being subject to potential distortion, in particular to fabrication on the part of a knowing and devious criminal. This danger was a common feature of Freeman’s stories: indeed, his first and probably best remembered novel, The Red Thumb Mark (1906), centered on the disturbing proposal that the newest and most publicly acclaimed form of trace evidence—fingerprints—could be forged. This distortion of the evidentiary power of traces, in turn, depended on public (and criminal) knowledge that traces could disclose and thus, if altered, could deceive.

Following The Red Thumb Mark, fingerprinting rarely figures as an important component of Thorndyke’s engagement with crime scene traces. Instead, Freeman features more subtle objects of interest—hair, fiber, and, of course, dust. Dust plays a special role in stories involving the criminal manipulation of trace evidence, in that, being the least understood, it is most resistant to distortion. Hairs, fibers, and other qualitatively recognizable crime scene fragments planted by knowledgeable culprits were commonplace in Thorndyke’s experience, but the dust that escaped their attention exposed their machinations. At the climax of one such tale, in which the dust produced by wood-boring insects negated the presence of mustache hairs found at the scene, Thorndyke acknowledges the advantage conferred on dust analysts:

I imagine that there will be very few persons in the world who could identify these particles in a collection of miscellaneous dust. And therein lay the value of this discovery; for if the significance of the hairs was open to doubt, that of the wood certainly was not. There was no question of its having been purposely planted.⁷⁴

But as dust analysis begins to penetrate public consciousness (in Thorndyke’s world, at least), its resistance to manipulation becomes more complicated. To illustrate this I return to the 1933 novel Dr Thorndyke Intervenes, which I used earlier to explore Freeman’s displacement of “celebrity pathology.” The story features the opening of a burial vault some eighty years following the death of its occupant, but, in yet another frustration to the expectations of a body-driven narrative, the coffin contained no corpse. This discovery ultimately led to the unraveling of a complex inheritance scam, and this in turn depended on Thorndyke’s appreciation of the condition of the tomb’s environment. Jervis, again undercutting the potential for gothic indulgence, describes the exhumation scene as follows:

There was nothing very sensational to see. The little chamber was crossed by a thick stone shelf on which rested the coffin. The latter had a very unattractive appearance, the dark, damp oak … being covered with patches of thick, green mildew and greasy-looking stains, over which was a mantle of impalpably fine grey dust. A layer of similar dust covered the shelf, the floor and every horizontal surface, but nowhere was there the faintest sign of its having been disturbed. On coffin and shelf and floor it presented a perfectly smooth, unbroken surface.⁷⁵

But it was the scene’s very lack of sensation that held the key to the mystery of the corpseless coffin—in particular the unbroken surface of the mantle of dust. Analysis of the tomb dust revealed a qualitative characteristic that did not match the ecological conditions within which it had settled. Here is Thorndyke’s explanation:

The dust that was there had not been disturbed since it was deposited. But it had not the characteristics of ancient dust, or of any dust which might have become deposited in a vault above ground which was situated in an open burial ground, remote from any dwelling house … . The dust which would be deposited in a vault over a period of eighty years would consist of very light and minute particles of matter, such as would be capable of floating in still air. There would be no mineral particles excepting excessively minute particles of the lighter minerals, and very few of these. Practically the whole of the dust would consist of tiny fragments of organic matter, of which a large part would be derived from textiles. As these fragments would be of all sorts of colours, the resulting dust would be of no colour at all; that is to say, of a perfectly neutral grey. But this dust was not of a perfectly neutral grey. It had a very faint tinge of red; and this extremely faint tinge of colour was distinguishable in the whole of the dust, not only in one part.⁷⁶

The color and composition of the dust, moreover, enabled Thorndyke to determine that it had originated in a single room, furnished with a carpet that had a red ground with a pattern principally of green and blue with a little black, and a cotton drapery dyed darkish blue. The conclusion was obvious: the dust at the tomb had been artificially spread by the conspirators in order to cover the traces they had made on the original layer of dust during their earlier exhumation. Thorndyke obligingly explained how this had been accomplished: the conspirators had taken dust vacuumed from the room to the vault, and had then blown it upwards by reversing the valve of the vacuum. The room dust then “floated in the air and settled down eventually in a perfectly even manner on the coffin, the shelf, and the floor, producing exactly the appearance that was seen.”

Smart, but not smart enough: the criminals had understood crime scene dust as surface, significant in its capacity to signify action through being marked. In this sense they had imbibed the basics of Gross’s vision, anticipating a mode of investigation that would look to reassemble movements in space and time through a systematic interrogation of the crime scene. What they had failed to appreciate was that there was a further dimension to dust—that, properly harvested and analyzed, it could be reconstituted as a distinctive and qualitative object in its own right. As Thorndyke explained:

To most persons, dust is just simply dust; a material quite devoid of individual character. Few people realize consciously that dust is merely a collection of particles detached from larger bodies, and that when those particles are magnified by the microscope, they reveal themselves as recognizable fragments of those bodies. If our friends blew dust into the vault, it would be dust that had been collected ad hoc and would be demonstrably the wrong sort of dust.⁷⁷

Conclusion: Dust’s Legacy

To conclude, I want to return briefly to the forensic uses of dust in the real world, and to reflect on the way literary representations might have had an effect at a practical level. The first point is a very general one: literary narratives like the Thorndyke stories brought dust to a different audience than that addressed by Gross and Locard and, freed from the constraints of a forensics of practice, enabled unalloyed demonstrations of the evidentiary powers of dust. But as his framing comments suggest, Freeman also saw his work as contributing to a shift in forensic sensibilities at the level of practice. Here he is an ally of contemporary dust theorists, who in their careful delineation of the crime scene sought to instantiate a new investigative regime. There are indications that in this Freeman met with some success. One instance will have to suffice: in the 1924 English edition of Gross’s Handbook, the editor inserted an inventory of the equipment that all investigators should have on hand at the crime scene. These items, he informed his readers, were known collectively as “the Thorndyke equipment.”⁷⁸

A more general interest in the forensic possibilities of dust is also discernible in the writings of English forensic commentators from the 1920s and 1930s, both as a topic in its own right and as part of broader discussion on the value of trace evidence—though not nearly as extensively as in the writings of their Continental counterparts.⁷⁹ These discussions, moreover, were registered at the level of policy. A parliamentary question to the home secretary in February of 1932, for example, asked whether the methods of dust analysis outlined by “foreign police experts” such as Locard were being adopted by the Metropolitan Police. The reply showed an official awareness of, if not full commitment to, this new forensic vista: “Careful scientific examination of dust is made wherever necessary, and although such cases are rare, the best technical assistance has been obtained whenever there has been ground for supposing that it was likely to be of value.”⁸⁰

A final example of dust’s reach into interwar practice is the instructional pamphlet prepared by the Home Office in 1936 and issued to all investigating officers following the establishment of the Metropolitan Police Laboratory in the previous year. The pamphlet is cast within a clearly Grossian approach to crime scene management—the need to preserve its integrity; the techniques, tools, and attitudes required; and the attention to recording that would guarantee the viability of crime scene vestiges at subsequent stages of inquiry. The ultimate referent for all this procedural diligence was left in no doubt:

The methods used by scientists today are so very exact that many definite conclusions can be drawn from material which, owing to its diminutive size, might easily be overlooked … . It may be something [the criminal] has dropped; some minute personal fragment; a hair, a piece of skin … . Even a few fine grains of dust may provide convincing evidence of guilt.⁸¹

Though dust as a particular instance of trace evidence did feature in discussions of crime scene investigation, it was not as a practical evidentiary object that it left its mark on the early twentieth-century forensic landscape. When analysts in the newly established police laboratories trained their microscopes on the “mute witnesses” salvaged from actual crime scenes, they were of a type that we would find more immediately recognizable: blood, hair, fibers. And yet the work of dust was not lost. This is because of its singular capacity to exemplify the conceptual and operational demands of an ascendant forensic paradigm, one whose main components of spatial delineation, systematic recording, and laboratory analysis of a world of seemingly inauspicious traces are clearly recognizable in the gestures and sensibilities of our own collective forensic imagination.