Mummification is usually associated with deliberate ritual practice, from the embalmers of ancient Egypt to the salt-packing techniques documented in historical funerary customs. But nature occasionally produces the same result on its own. Salt works as a preservative through two complementary mechanisms. First, it is strongly hygroscopic, drawing water out of tissue by osmosis and creating a desiccated state in which the chemical reactions of decay slow dramatically. Second, high salinity is antimicrobial: most of the bacteria that drive putrefaction cannot tolerate concentrated brine, so the microbial ecosystem that normally dismantles a corpse simply collapses. Deprived of both moisture and microbes, soft tissue can survive for months, years, or even millennia.

The archaeological record is full of proof. The most famous examples are the salt men of Chehrābād in northwestern Iran, miners who perished in collapses at the Douzlākh salt mine as early as the fourth century BC and were preserved so completely that ancient DNA, isotopic signatures of their diet, and even the fibers of their clothing have been recovered. Previous laboratory work, including experiments in which human tissue was deliberately mummified in salt, has confirmed how rapidly salt halts both microbial growth and DNA degradation. Yet despite this rich archaeological literature, no forensic scientist had ever documented a naturally salt-mummified body in a contemporary medico-legal context, until now.

The French case is unusual not only because it happened at all, but because of where it happened. Unlike the Iranian salt men, who were entombed in a dry, cool salt mine, this body was found in a warm, humid, anthropogenic saline environment, a human-made salt production setting in the Mediterranean south of France. The region has a seventy-year history of managed coastal salinas, shallow basins where seawater is evaporated to harvest salt, and abandoned sites where hypersaline water pools and crystallizes under the intense Provençal sun. Local geochemical studies of nearby lagoons such as Lavalduc have documented active precipitation of halite, the mineral form of sodium chloride, in and around these basins. It was in this evaporative, salt-saturated setting that the body lay undisturbed long enough for a crystalline shell to grow around it.

External examination revealed a completely desiccated body, brown and leathery in appearance, with the facial features and the morphology of the limbs and extremities remarkably preserved. That degree of anatomical integrity is forensically valuable: it allowed the team to attempt a biological profile of the deceased, the standard assessment of sex, age, and body characteristics that forms the first step toward identification. In many decomposed or skeletonized bodies, such profiling is severely compromised by tissue loss. Here, the salt had effectively frozen the external anatomy in place, demonstrating that natural mummification can paradoxically make a body more identifiable, not less.

Autopsy, however, told a more complicated story. Inside the leathery exterior, the researchers found extensive tissue desiccation consistent with prolonged exposure to a highly saline environment, but the preservation was strikingly uneven. Some regions showed classic mummified changes, while others displayed focal putrefactive alteration, including complete liquefaction of the brain. This hybrid pattern, in which desiccation and decay coexist in the same body, had not previously been described in the modern forensic literature. The authors attribute it to the specific dynamics of the anthropogenic saline setting: fluctuations in salinity, intermittent moisture, and ambient heat likely allowed pockets of decomposition to proceed before full desiccation took hold, producing a mosaic of preservation that contrasts with the uniform mummification seen in mine contexts.

The case also illustrates the hard limits of forensic science when preservation is this unusual. Toxicological analyses of visceral samples came back negative for drugs and toxic substances, ruling out chemical causes of death detectable in the preserved tissue. DNA analysis and fingerprint examination were both performed, but neither produced an identification. The failure is instructive. Even when tissue appears well preserved, the same osmotic and chemical stresses that stop decay can fragment genetic material in ways that defeat standard amplification, and desiccated skin often cannot yield usable friction ridge prints. For the identification effort, the team had to fall back on contextual and morphological evidence rather than laboratory confirmation.

Perhaps the most innovative part of the investigation was environmental. Rather than relying solely on the body itself, the researchers reconstructed the salinity dynamics, evaporation rates, and local climate conditions of the site, and used that reconstruction to support a tentative hypothesis about the post-mortem interval, the elapsed time since death. The logic is analogous to entomological dating, where insect development stages clock the interval, but here the clock is geochemical: the thickness of the salt crust, the rate at which brine evaporates under the regional climate, and the seasonal behavior of the saline basin together constrain how long the body must have lain there. The authors emphasize that this estimate is tentative, but the approach itself is a proof of concept for reading time from the environment in cases where conventional markers are absent.

The report arrives amid growing attention to what forensic scientists call complex bodies, remains whose preservation state falls outside the familiar categories of fresh, decomposed, skeletonized, burned, or water-immersed. Recent systematic reviews and procedural proposals have argued that such cases demand a multidisciplinary response, combining pathology, anthropology, radiology, genetics, toxicology, entomology, botany, and environmental science, guided by standardized on-site inspection protocols such as those developed by the European Council of Legal Medicine. The salt mummy of southern France is a textbook argument for that approach: no single discipline could have interpreted the body, but the combined evidence of morphology, chemistry, and environmental reconstruction extracted real forensic information from an apparently intractable case.

For the wider forensic community, the implications are twofold. First, investigators encountering desiccated remains in or near saline environments, from abandoned salinas to industrial brine facilities, should now consider natural salt mummification as a genuine possibility rather than a curiosity confined to archaeology. Second, the case expands the known range of environments capable of natural preservation into warm, humid, human-modified settings, which means the global geography of potential salt mummies is far larger than the arid mines and deserts of the archaeological record. As the authors conclude, environmental analysis and multidisciplinary investigation are essential tools for identification and post-mortem interval estimation in complex bodies, and this unique case, a man sealed in salt under the Mediterranean sun, may be only the first of its kind to surface.

Subject of Research: Natural salt mummification of human remains in a forensic context

Article Title: Natural salt mummification in a forensic context: a case report and environmental considerations

Article References: Delteil, C., Zuck, S., Capuani, C., Carballeira-Alvarez, A., Ardagna, Y., & Tuchtan, L. (2026). Natural salt mummification in a forensic context: a case report and environmental considerations. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-04040-4

Image Credits: AI Generated

DOI: 10.1007/s00414-026-04040-4

Keywords: salt mummification, forensic pathology, mummification, post-mortem interval, forensic anthropology, decomposition, halite, saline environment, taphonomy, case report, DNA analysis, environmental forensics

The study, published as an open-access technical note in the International Journal of Legal Medicine, was carried out by Simona A. Dinu, Iris Sluis, Wilma Duijst and Tristan Krap, with bones obtained through the body donation program of Amsterdam University Medical Centers. The team worked with humeri, tibiae and femora from four donors: two women aged 80 and 84 whose bones had been stored in closed buckets at 4 degrees Celsius for one to two years, a 91-year-old man whose bones were processed within three days of death, and a 78-year-old man whose body was exhumed after two years of burial. These three categories, fresh, controlled aged and taphonomically altered, allowed the researchers to test whether their methods could survive contact with real-world decomposition.

The preparation method builds on a classic manual technique originally described by Frost in 1958 and later updated by Maat and colleagues. Bone pieces roughly two millimeters thick are cut with a handsaw, then wet-ground on waterproof sanding paper attached to a glass slab until translucent. But the team found two crucial improvements were needed. First, polishing with fine P1000 sandpaper proved insufficient to remove the scratches left by coarse grinding, so they recommend finishing with P2000 grit. Scratches matter enormously in stained specimens because dye particles tend to lodge in them, obscuring the very structures researchers want to see. Second, the team added an ultrasonication step: bone slices were submerged in tap water with a few drops of dish soap and ultrasonicated for two hours to flush microscopic grinding debris out of the Haversian canals. Without this step, debris particles bind dyes eagerly and produce specimens cluttered with artifactual coloration around the canals.

Another key innovation is a brief acid etching step adapted from a protocol by Osborne and Curtis. Before some staining procedures, slices are submerged in 1 percent formic acid for five minutes, rinsed, then placed in 70 percent ethanol for twenty minutes. This short, low-concentration treatment roughens the mineral surface and exposes the underlying protein matrix, giving dyes more contact area to bind, without decalcifying the tissue, which would require far longer exposure. The effect was dramatic: without acid etching, Hematoxylin and Eosin, Sirius Red and Fast Green, and Toluidine Blue all produced poor or nearly featureless coloration. With etching, the same dyes yielded crisp, reproducible images. Interestingly, for Masson’s Trichrome and Azocarmine G, which already stain well, etching caused overstaining and actually reduced the amount of visual information available.

The five stains were chosen from a 2025 review by Sluis and colleagues that compiled 45 dyes potentially suitable for anthropological applications. Three of them, Hematoxylin and Eosin, Toluidine Blue and Azocarmine G, were selected for their ability to reveal microstructure. H&E enhanced the concentric and interstitial lamellae that are barely visible in unstained ground sections, and selectively colored some osteons and cement lines. Toluidine Blue proved excellent for visualizing cement lines with minimal background, clearly delineating the contours of osteons and also coloring the edges of osteocyte lacunae. Azocarmine G, which binds acidic cellular components, distinguished osteons sharply from adjacent interstitial bone and stained them uniformly from the Haversian canal to the cement line. The remaining two stains, Sirius Red and Fast Green and Masson’s Trichrome, target composition: Sirius Red binds collagen while Fast Green binds non-collagenous proteins, and Masson’s Trichrome similarly separates intact collagen from denatured collagen and other proteins.

The compositional stains produced the most striking findings. Fresh bone stained predominantly red with Sirius Red and Fast Green, consistent with its high collagen content, while the controlled aged and taphonomically altered bones stained predominantly green, indicating that most collagen had already degraded during the two-year storage or burial periods. This result contrasts with earlier studies by Jellinghaus and colleagues, who found that human bones buried for up to 45 years still retained substantial collagen. The authors suggest several possible explanations: the controlled aged bones were not intact, leaving them more exposed to degradative factors, and climate conditions at the deposition site can dramatically accelerate decomposition, with early taphonomic changes exerting the strongest influence on the bone’s diagenetic trajectory. Masson’s Trichrome told a complementary story, with red and violet regions signaling non-collagenous proteins appearing within some osteons and at the outer edges of taphonomically altered slices, precisely where exposure to the burial environment is greatest.

The microstructural stains also revealed biologically meaningful patterns. Some osteons showed much stronger affinity for the dyes than others, and the researchers attribute this to their newer formation: young osteons contain more of the organic protein matrix, including acidic proteins like osteopontin and bone sialoprotein produced by osteoblasts, and these osteons tend to sit toward the periosteum where bone formation outpaces resorption. Toluidine Blue’s staining of cement lines is particularly valuable because cement lines are rich in negatively charged sulfated mucosubstances that interact strongly with this cationic dye, and the dye’s effectiveness depends critically on the pH of the solution. Tracing cement lines allows researchers to follow remodeling events through the bone, and the extent of remodeling correlates with age, mechanical stress and lifestyle, information that can support, though never replace, conventional age-at-death estimation.

The practical advantages of the approach are considerable. Because fixation, decalcification and embedding are all eliminated, fixation being optional and decalcification and embedding avoided entirely, a stained bone sample can be prepared within a single day rather than over several weeks. The mineral matrix is preserved as a background against which changes in the organic portion of the bone can be read, which is especially important for specimens in advanced decomposition where most organic material has already degraded. The method is inexpensive, uses low-hazard chemicals, and requires relatively little training. The authors also demonstrated reproducibility: specimens prepared in duplicate and stained by two separate researchers showed little to no variation, and results were consistent across staining sessions separated by more than a year, and across humeri, tibiae and femora.

The researchers are candid about the limitations of the manual grinding method. Slide thickness cannot be precisely controlled, which produces variations in brightness and makes even focusing difficult, and handling artefacts such as cracks risk being misclassified as genuine taphonomic alterations, potentially leading to wrong conclusions about how degraded a sample really is. Mechanical stress from grinding could also affect the organic matrix in samples with poor collagen quality. Precise instruments like diamond blade saws could solve some of these problems but at considerably higher cost. The team also notes that image acquisition itself needs standardization, since two different microscope cameras produced noticeably different color renderings of the same slides, and inconsistent white balance or exposure could skew interpretation of color patterns in future studies.

Overall, the study represents a first step toward making histochemistry a standardized tool in forensic and anthropological casework. By demonstrating that five widely available stains can be reliably applied to unfixed, undecalcified, unembedded human bone, whether fresh, refrigerated or altered by two years of burial, the researchers have laid the groundwork for adapting many more of the 45 candidate dyes identified in their earlier review. Combined with automated image analysis, which could reduce the subjectivity that currently ties structure identification to individual researcher experience, stained bone histology could eventually support age and lifestyle predictions and post-mortem interval estimation for skeletonized remains, turning the chemistry of dyes into a new language for reading the dead.

Subject of Research: Histological staining protocols for unfixed, undecalcified human bone in forensic anthropology

Article Title: A technical note on the preparation and staining of unfixed, undecalcified and unembedded fresh and taphonomically altered human bone with five common stains and dyes

Article References: Dinu, S. A., Sluis, I., Duijst, W., & Krap, T. (2026). A technical note on the preparation and staining of unfixed, undecalcified and unembedded fresh and taphonomically altered human bone with five common stains and dyes. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-03986-9

Image Credits: AI Generated

DOI: 10.1007/s00414-026-03986-9

Keywords: forensic anthropology, bone histology, histological staining, human bone, taphonomy, collagen degradation, Hematoxylin and Eosin, Sirius Red, Toluidine Blue, Masson's Trichrome, Azocarmine G, post-mortem interval

The review, conducted by an international team led by researchers at Universiti Malaya in Kuala Lumpur, followed PRISMA 2020 guidelines and was registered on PROSPERO. The team searched PubMed, Scopus and Web of Science for peer-reviewed studies published between January 2015 and December 2025 that used spectroscopic methods to estimate the post-mortem interval, or PMI, of skeletal remains. From 167 initial records, 88 duplicates were removed and, after screening, 19 studies made the final cut. Risk of bias was assessed with the Joanna Briggs Institute critical appraisal tool, and every included study scored 6.0 or above, indicating moderate to high methodological quality across the board.

The technologies at the heart of this field are Fourier-transform infrared spectroscopy, known as FTIR, and Raman spectroscopy. FTIR was the most frequently used modality, appearing in ten of the 19 studies, most commonly in its attenuated total reflection configuration, while Raman spectroscopy featured in seven. Both techniques probe the molecular structure of skeletal tissue, but in different ways. Infrared spectroscopy measures how chemical bonds absorb mid-infrared light, typically across the 400 to 4000 per centimetre range, revealing the composition of the mineral phase and the organic matrix. Raman spectroscopy, by contrast, detects the tiny shifts in wavelength produced when laser light scatters inelastically off molecular vibrations, offering the practical advantage of being largely unaffected by water, which makes it well suited to hydrated or minimally prepared specimens.

The molecular targets of these analyses are the building blocks of bone itself. Bone consists of poorly crystalline carbonate-substituted hydroxyapatite embedded in a matrix dominated by type I collagen, while tooth enamel is far more heavily mineralised and crystalline. As bone degrades after death, measurable changes accumulate: the crystallinity index shifts, carbonate-to-phosphate ratios drift, collagen-related amide bands weaken, and the balance between mineral and organic content changes. Studies in the review typically acquired around 120 scans per spectrum at resolutions of 2 or 4 per centimetre, then extracted peak intensities, integrated band areas and derived ratios. Energy-dispersive X-ray spectroscopy, the second most common technique, added an elemental dimension, tracking calcium, phosphorus and trace elements such as barium, zinc and iron whose distributions shift with depositional environment and time.

The evidence base is strikingly diverse. Sample sizes ranged from 6 to 145 specimens, drawn from human remains in most studies and from domestic pigs, Wistar rats and Eastern grey kangaroos in four. Nine studies combined forensic and archaeological material, with archaeological specimens originating from burial sites across Italy, Spain, Slovenia, Portugal and Austria, including remains recovered from World War II mass graves. The femur was the most analysed bone, followed by ribs, skull bones and tibiae, while dental studies focused on incisors and molars. Depositional environments spanned surface exposure, burial, indoor storage and even freshwater and saltwater immersion. Notably, 58 percent of the included studies built directly on the foundational work of Nagy and colleagues and Patonai and colleagues, published before 2015, underscoring how heavily the field leans on a small number of seminal papers.

Where spectroscopy shines brightest is in separating the old from the very old. Several studies reported consistent discrimination between forensic and archaeological remains, reflecting cumulative diagenetic changes that unfold over decades and centuries. Machine-learning models integrating spectral data achieved classification accuracies ranging from 58 to 100 percent. Among the standout results, an orthogonal partial least squares model built on Raman data achieved a root mean square error of cross-validation of 1.25 years with a cross-validated coefficient of determination of 0.89. A genetic algorithm-assisted PLS model trained on second-derivative FTIR spectra predicted PMI with an error of 54.36 days for buried samples and 68.48 days for unburied ones. A logistic regression model combined with receiver operating characteristic analysis correctly classified 87 percent of samples with a ten-year PMI, 76 percent at 25 years and 80 percent at 50 years.

Yet the review also exposes a critical weakness: the first 90 days after death remain stubbornly opaque. Studies evaluating shorter post-mortem intervals frequently reported weaker or statistically insignificant associations, with differences between sample groups sometimes failing to reach significance at p greater than 0.05. The authors attribute this to the interplay of intrinsic biological factors with extrinsic environmental conditions, which produce different kinetics of bone degradation in the earliest stages. In that window, decomposition-related biochemical changes are simply too subtle to rise above biological and environmental noise. This matters because the early post-mortem period is precisely where conventional methods still work, meaning spectroscopy currently struggles most where it is least needed, and performs best where no alternative exists.

Environmental context emerged as one of the principal sources of variation. Ultraviolet radiation, burial conditions, aquatic immersion and storage conditions all altered the rate and extent of physicochemical change in skeletal tissue. One study showed that environmental conditions changed the expression of commonly used FTIR markers, while another reported distinct elemental profiles depending on depositional environment, and a third linked changes in elemental composition to soil interactions and fracture-related alterations in bone hydration. These findings align with established taphonomic principles, in which temperature, moisture, microbial activity, oxygen availability and soil chemistry collectively shape skeletal diagenesis. The implication is clear: spectral markers cannot be interpreted in isolation from the environment in which remains were deposited, and future predictive models must incorporate environmental variables alongside spectral parameters.

Biological variability adds a second layer of complexity. Animal models, particularly pigs, are widely used as analogues for human decomposition, but the review found that spectral patterns in animal remains were not always concordant with those in human samples, especially for phosphate-related parameters and mineral-to-organic matrix indices. Differences between skeletal tissues also matter: one study observed a decrease in the carbonate-to-phosphate ratio in teeth that ran counter to trends commonly reported in bone, likely reflecting the differences in mineral content, crystallinity and hydroxyapatite structure between the two tissues. Limited evidence even hints at sex-related differences in the magnitude of spectral change, although the overall direction of decomposition trends appears consistent between males and females.

The path forward, the authors argue, lies less in discovering new biomarkers than in standardising and validating the ones already known. Carbonate-to-phosphate ratios, crystallinity indices, collagen-related bands and mineral-to-organic matrix ratios have shown reproducible temporal trends across independent studies and now deserve large-scale, multicentre validation on human remains under realistic depositional scenarios. Machine learning will be central to that effort, but the review cautions that most existing models were built on small datasets and lack external validation, and that the limited interpretability of some algorithms may hinder forensic admissibility under legal standards such as Daubert, which demands tested, peer-reviewed methods with known error rates. The reviewers also call for multimodal integration, combining spectroscopy with micro-computed tomography or X-ray diffraction, and for greater attention to dental tissues, which remain underexplored. Spectroscopy, in short, has proven it can read the chemical autobiography written into bone. What remains is to teach it to testify.

Subject of Research: Spectroscopic estimation of the post-mortem interval of skeletal remains

Article Title: Post-mortem interval estimation of skeletal remains using spectroscopic analysis: a systematic review

Article References: Thrukkumar, S., Rahmat, R. A.-A., Soon, L. P., Hamdan, S. N. S. M., Rizky, B. N., Kurniawan, A., Humphries, M., Sani, S. F. A., Ibrahim, N., Rahim, A. H. A., Suzuki, T., & Linacre, A. (2026). Post-mortem interval estimation of skeletal remains using spectroscopic analysis: a systematic review. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-04010-w

Image Credits: AI Generated

DOI: 10.1007/s00414-026-04010-w

Keywords: forensic science, post-mortem interval, spectroscopy, FTIR, Raman spectroscopy, skeletal remains, bone diagenesis, machine learning, chemometrics, taphonomy, forensic taphonomy, systematic review

The review’s methodology tells its own story. De-Giorgio and Benedetti searched PubMed, Scopus, and Web of Science without date restrictions, combining AFM-related terms with post-mortem and autopsy keywords, and screened references manually to catch anything the databases missed. Despite the breadth of the search, only five original research articles met their strict criteria of focusing on human post-mortem materials with forensic relevance. That number is striking. AFM has been embraced enthusiastically in materials science, nanotechnology, biology, and clinical medicine for decades, yet its application to the tissues of the deceased remains in its infancy. The five qualifying studies concentrated on just four substrates: bone, skeletal muscle, tendinous tissue, and hair. This scarcity, the authors argue, reflects a combination of high instrumentation costs, small sample sizes, and substantial methodological heterogeneity that has kept the field fragmented.

Bone emerges as the most scientifically mature substrate in the review. Building on earlier animal studies that mapped elastic and inelastic deformation behavior and visualized the lacunar-canalicular network with exceptional precision, researchers turned to human autopsy samples to probe age-related changes in bone composition. In one key investigation, Milovanovic and colleagues characterized mineral grain size in bone harvested from the lateral femoral neck of two groups of women: young women aged 20 to 40 and elderly women aged 73 to 94. The older cohort exhibited larger and more heterogeneous mineral grains, a structural condition associated with reduced mechanical resistance. Crucially, chemical analysis of calcium and phosphorus levels revealed no significant differences between the groups, ruling out a major confounder and reinforcing the validity of the purely structural observations.

A follow-up study translated those structural differences into mechanical terms using AFM-based nanoindentation. The technique works by applying a controlled force to the sample surface and recording the corresponding force-distance curves, from which local mechanical properties can be computed with precision. The results showed that the differences in mineral grain size between young and elderly women translated into distinct elastic behaviors, with significantly reduced elasticity in the elderly group, an effect closely linked to higher fracture susceptibility. Although limited by sample size, the work demonstrated a reproducible methodological framework that the review’s authors believe could be extended to contexts far more directly relevant to forensic investigation, including the characterization of fracture margins in cases of suspected trauma.

It is in forensic traumatology that the review’s most provocative proposals appear. AFM topography and force mapping can quantify nanoscale roughness, microcrack patterns, and local stiffness gradients along fracture edges, capabilities that could support the differentiation between perimortem trauma, injuries inflicted around the time of death, and post-mortem damage that occurred afterward. One high-impact translational scenario involves cardiopulmonary resuscitation. CPR is well recognized to generate rib fracture patterns that can complicate post-mortem interpretation, sometimes mimicking injuries inflicted by an assailant. AFM could add objective surface and mechanical descriptors to complement macroscopic evaluation, radiology, and conventional microscopy, helping pathologists distinguish resuscitation artifacts from thoracic fractures unrelated to resuscitative maneuvers. In an era when CPR-related rib injuries are common and medico-legal disputes over their origin are frequent, such a tool could prove decisive.

Bone is also highly informative in cases of thermal exposure, including fires and explosions. Experimental work has shown that heating produces progressive physicochemical and structural modifications of bone mineral: crystallite parameters begin to change at temperatures of 500 degrees Celsius and above, while marked crystallite growth and recrystallization become prominent at higher temperatures, commonly reported around 700 degrees Celsius and beyond, with downstream effects on the stability and fragility of calcined remains. Post-mortem computed tomography, or PMCT, has already proven valuable in assessing burned victims, including the recognition of typical heat-related changes and the differentiation of heat-related fractures from traumatic ones. The review proposes a correlative framework in which PMCT provides non-destructive, case-level documentation of fracture patterns, ATR-FTIR spectroscopy and X-ray diffraction characterize temperature-related mineral and matrix transformations, and AFM targets selected regions for nanoscale topographic and nanomechanical mapping. The open question is whether thermal overprinting modifies or preserves the nanoscale features relevant to forensic interpretation, and AFM is positioned to answer it.

Soft tissue tells a different story, one in which water plays an unexpectedly large role. Studies on human iliotibial band samples investigated how variations in water content influence the mechanical properties of post-mortem soft tissues, and the findings were clear: lower water content increases the elastic modulus of the tissue. This has direct implications for anyone designing experiments on post-mortem soft tissues, since hydration status must be controlled for or at least reported. With specific regard to estimating the post-mortem interval, the elapsed time since death and one of the central questions in forensic practice, De-Giorgio and colleagues performed a preliminary investigation on skeletal muscle samples collected at different post-mortem intervals, applying AFM-based measurements of the Young’s modulus and hysteresis, the latter reflecting energy dissipation during loading cycles. Their results indicated that hysteresis is less influenced by inter-individual variability than the elastic modulus, making it a parameter worth prioritizing in future PMI-focused studies. This matters because traditional PMI methods, which rely on qualitative assessment of livor mortis, rigor mortis, and algor mortis, are fundamentally constrained by the examiner’s subjective evaluation and by intrinsic factors including age, sex, muscle mass, and ambient temperature.

Hair, remarkably durable and easy to sample, offers a third window into the post-mortem nanoworld. Mansilla and colleagues compared hair samples from contemporary autopsies with those from archaeological mummies to examine nanostructural cellular features. Compared with modern hair, the mummy samples exhibited a depletion of fatty acids and a reduction in the regularity of the cuticular scale pattern, although the scales themselves remained remarkably preserved even after centuries. The review’s authors suggest extending this analytical approach by comparing mummy hair across different historical periods and geographic regions, potentially revealing correlations between long-term environmental exposure and nanostructural hair alterations. Such a comparative framework could eventually help investigators assess whether remains are consistent with a claimed historical context or with a more recent death.

Perhaps the most forward-looking sections of the review concern substrates that have barely been touched in forensic settings. Skin, which has been extensively investigated with AFM in dermatological research on the epidermis and dermis, remains underexplored in forensic pathology, despite the fact that establishing wound vitality and age is often critical for medico-legal reconstruction and remains methodologically challenging. AFM-derived parameters such as surface topography, local stiffness mapping, and viscoelastic signatures could be investigated for their association with the post-trauma interval, provided that major confounders including hydration status, sampling site, and fixation protocol are explicitly controlled. The authors also point to dried bloodstains, where experimental studies have used AFM to estimate stain age by tracking changes in the mechanical properties of red blood cells over time, with subsequent work showing that substrate type, whether glass, metal, or ceramic, significantly affects the mechanical signature. Gunshot residue analysis represents another avenue, since AFM has already been applied to high-resolution characterization of GSR particle morphology and size distribution, with evidence that particle size distributions may vary as a function of shooting distance. Extending such analyses to peri-wound skin at entry and exit sites could reveal reproducible patterns related to muzzle-to-target distance and ammunition type. Even the subtle electrical current mark seen in electrocution victims, currently assessed mainly through histopathology and scanning electron microscopy with energy-dispersive X-ray analysis, could yield additional microfeatures to AFM’s nanomechanical mapping.

The review is candid about the obstacles standing between these visions and courtroom reality. The evidence base is constrained by small sample sizes, high instrumentation costs, and methodological heterogeneity spanning differences in sampling, preparation, AFM operational modes, and reporting standards. To support AFM as a reliable forensic tool, and ultimately strengthen its potential admissibility in court, the authors call for robust statistical reporting including appropriate summary measures, dispersion indices, and explicit assessment of reproducibility and measurement uncertainty. They also advocate multicentric research designs to increase sample representativeness and distribute financial and logistical burdens, along with standardized post-mortem imaging biobanks built on harmonized acquisition protocols to facilitate cross-study comparison and accelerate the integration of AFM-based metrics into forensic science. Bone, skeletal muscle, and hair remain the most practical starting points, being generally accessible at autopsy and collectable with limited manipulation. If those foundations are laid, the nanoscale may soon become a routine crime scene, one measured not in meters but in nanometers.

Subject of Research: Applications of atomic force microscopy to human post-mortem tissues in forensic medicine

Article Title: Atomic force microscopy in human post-mortem samples: current applications and future directions

Article References: De-Giorgio, F., & Benedetti, B. (2026). Atomic force microscopy in human post-mortem samples: current applications and future directions. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-03976-x

Image Credits: AI Generated

DOI: 10.1007/s00414-026-03976-x

Keywords: atomic force microscopy, forensic science, post-mortem interval, forensic pathology, bone nanomechanics, nanoindentation, skeletal muscle, mummified hair, thermal bone alteration, wound age estimation, gunshot residue, legal medicine

Forensic entomology, the discipline that applies knowledge of insect taxonomy, biology, ecology and physiology to legal investigations, rests on three main pillars. The first is temperature-dependent development: insects grow at predictable rates that vary by species and population, so if investigators know the temperatures experienced by the earliest colonizers, they can estimate a minimum post-mortem interval, abbreviated minPMI, for relatively recent deaths. The second is the well-established pattern of colonization, in which different insect species arrive at a cadaver in a broadly predictable sequence, allowing estimates of longer post-mortem intervals based on the community of insects present on the remains. The third is habitat and phenology specificity, meaning that some species occupy particular environments or appear only in certain seasons, which can help determine the season of death in historical cases and even reveal whether a body was moved from one location to another after death.

Among the insects that matter most in this field, two orders dominate: the flies, or Diptera, which are typically the first to arrive, and the beetles, or Coleoptera, which follow later. Within the flies, families such as Calliphoridae, the blowflies, and Sarcophagidae, the flesh flies, have received enormous scientific attention because they are conspicuous, abundant and relatively well studied. Other families, including Muscidae, Fanniidae, Piophilidae and Phoridae, are consistently found on human and animal cadavers worldwide, yet some of their members remain poorly understood in terms of biology, distribution and habitat preferences. The genus Fannia, small dark flies measuring just three to four millimeters, belongs to this understudied group, and its taxonomy continues to challenge specialists even as its forensic relevance becomes increasingly clear.

The Fanniidae are a family of small to medium-sized flies with a worldwide distribution, once lumped together with the Muscidae and now recognized as a distinct family comprising more than 300 species across five genera. The genus Fannia alone contains around 400 described species, of which 80 are listed in Europe. Its larvae are saprophagous, feeding on decaying organic matter, and have been reported from birds’ nests, animal burrows, fungi and excrement. The flies also have medical significance because certain species can cause gastrointestinal, urogenital and traumatic myiasis, the infestation of living tissue. Roughly 20 to 25 Fannia species have been recorded from pig cadavers used in field experiments as human decomposition models, but only a handful, including Fannia canicularis, Fannia fuscula, Fannia leucosticta, Fannia manicata, Fannia monilis, Fannia nigra, Fannia pusio and Fannia scalaris, have ever been found on human remains in Europe. In Italy, only F. scalaris and F. canicularis had been commonly reported from human cadavers, always in the larval stage, until now.

The new case came to light when entomological samples were collected during the crime scene inspection following the discovery of a body in an abandoned building in southern Italy, with additional sampling performed during the post-mortem analysis. The body lay on the floor of a room with partially open windows and was in an advanced state of decomposition, partially mummified and partially skeletonized. Combining circumstantial evidence with entomological analysis, the investigators estimated that death had occurred seven to eight months before the body was found. The specimens were collected and processed according to established best-practice guidelines, observed and photographed with a stereomicroscope, preserved in 80 percent ethanol, and identified using the available literature alongside comparison with previously identified samples held in a reference collection.

What the team found was a remarkably complex insect community: sixteen taxa in total, spanning nine species of Diptera from the families Calliphoridae, Muscidae, Fanniidae, Sphaeroceridae and Phoridae, six species of Coleoptera from the families Dermestidae, Cleridae and Ptinidae, and one species of Lepidoptera from the family Tineidae, the clothes moths. Among the flies, only Hydrotaea capensis was present as larvae, while all the other fly taxa were represented by puparia, the hardened barrel-shaped casings that fly larvae form when they pupate, found both closed and open. The beetles, by contrast, appeared as both larvae and adults. Every taxon collected was already well known from Italian modern and archaeo-funerary cases and from field experiments with pigs and other animal models, with one striking exception: several puparia of Fannia lineata, a species that, based on an extensive literature search, had never before been recorded from a human cadaver.

The composition of the entomofauna allowed the researchers to estimate that colonization began in spring, a conclusion that agreed with the circumstantial evidence available in the case. Previous records of F. lineata fit this picture. According to the standard taxonomic literature on European Fanniidae, the species has been found in bird nests, in rabbit burrows and in vertebrate cadavers throughout Europe, though rarely. In Italy, an earlier study had collected the species from pig cadavers in an advanced state of decay, recovering an adult from an exposed pig carcass and larvae from a buried pig that was regularly exhumed to study how disturbance affects the colonization of buried bodies. The new human case is therefore consistent with the species’ apparent association with advanced decomposition, while dramatically extending its documented range of substrates.

Beyond the record itself, the study’s most valuable contribution may be morphological. Fannia larvae are characterized by a dorsoventrally flattened body armed with fleshy processes and by posterior spiracles raised on stalk-like processes in the anal region, but while the adults and larvae of European Fanniidae have been well described, puparia have remained poorly documented. This gap matters because puparia often represent the majority of fly findings in old cases and in archaeological contexts such as crypts and tombs, and because puparia can undergo physical alterations during pupariation, including contraction that partially obscures fine details, while features like oral sclerites are not consistently visible in empty puparia. The researchers therefore described the puparium of F. lineata in detail, noting a suite of diagnostic characters: the puparia are smaller than those of the two Fannia species previously known from Italian human cadavers; dorsolateral processes are absent; the six posterior processes are smooth and unbranched; the dorsomedian posterior processes are smaller than the others; a thickened arched area connects the two dorsal processes on the seventh abdominal segment; the posterior spiracles protrude less than in F. canicularis and F. scalaris; and the distance between the two posterior spiracles is twice the space between each spiracle and the lateral edge of the segment.

To make these characters usable in practice, the authors also provided an identification key for the larvae and puparia of the Fannia species collected from human cadavers in Italy, allowing forensic analysts to distinguish F. lineata from its more familiar congeners even when only puparial remains are available. The team emphasizes that the finding highlights the need for further research into the habitat preferences, phenology and developmental rate of F. lineata, a species that, despite being only occasionally encountered, may provide additional information useful for answering the questions posed by magistrates in forensic contexts. As climate change continues to shift both the phenology and the distribution of necrophagous insects, and as forensic entomology gains ground in courtrooms around the world at very different speeds depending on the country, discoveries like this one quietly expand the forensic toolkit. A fly barely four millimeters long, overlooked for more than a century since its description in 1895, has now formally joined the ranks of insects that can testify, silently and precisely, about the circumstances of human death.

Subject of Research: First forensic record of the fly Fannia lineata on a human cadaver and description of its puparium for species identification.

Article Title: Contributions to the identification of Fannia lineata (Stein, 1895) (Diptera: Fanniidae) in forensic contexts: first record in a human cadaver

Article References: Vanin, S., Carta, G., Scopetti, M., & Santurro, A. (2026). Contributions to the identification of Fannia lineata (Stein, 1895) (Diptera: Fanniidae) in forensic contexts: first record in a human cadaver. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-03967-y

Image Credits: AI Generated

DOI: 10.1007/s00414-026-03967-y

Keywords: forensic entomology, Fannia lineata, Fanniidae, puparium identification, post-mortem interval, human decomposition, Southern Italy, Diptera, minimum PMI, insect succession, forensic science, identification key