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A correct assessment on the position, path, and direction of fracture lines is crucial when the sequence of different injuries on the skull has to be ascertained. In this context, the so-called Puppe's rule on intersecting fracture lines has always been considered a cornerstone of such an investigation. However, there is one factor that has never been previously considered: how do fracture lines behave when they reach the edges of an old and remodeled hole from a previous craniotomy? Two peculiar cases are presented of subjects undergoing cranial fractures due to blunt force trauma (case 1) and gunshot (case 2). Both previously underwent neurosurgical operations with persistence of the burr holes produced by the craniotomy drill (15 and 20 years before death). What was arguable, according to Puppe's rule, was that the fracture lines, when at the edge of the craniotomy hole, stopped. However, what has been detected was different than what expected: fracture lines continued exactly in the opposite direction, as though they were "skipping" the hole, following the same direction and the same axis and stopping a few centimeters over on the opposite side of the craniotomy hole. Puppe's rule has never been refuted, but these cases are the closest to an exception ever seen in forensic anthropology. [ABSTRACT FROM AUTHOR]

In the context of further impact tests with various striking weapons against the skull, it turned out that the manufacturer had incorrectly calibrated the force measuring plate, which was used in our earlier experiments. When the tests were carried out again under the same conditions, the measurement results were significantly higher. [ABSTRACT FROM AUTHOR]

The medical and biomechanical assessment of injuries from blows to the head is a common task in forensic medicine. In the context of a criminal justice process, the injury potential of different striking weapons is important. The article at hand compares the injury potential of assaults with a 0.5-l beer bottle and a 0.33-l Coke bottle, both made of glass. The research team hit 30 used empty 0.5-l beer bottles and 20 used empty 0.33-l Coke bottles manually on an aluminum dummy skull set on a force measuring plate, using acrylic and pork rind as a scalp surrogate. There was no significant difference in fracture threshold and energy transfer between the examined beer and Coke bottles. Both glass bottles are able to cause fractures to the facial bones while cranial bone fractures are primarily not to be expected. Blows with a 0.5-l beer bottle or with a 0.33-l Coke bottle to the head can transfer up to 1.255 N and thus are able to cause severe blunt as well as sharp trauma injuries. [ABSTRACT FROM AUTHOR]

The formation of skull fractures is an important topic in legal medicine. In particular, the influence of boundary conditions is controversially discussed in the literature. A study focusing solely on this aspect was missing. This study aimed to investigate the influence of boundary conditions on the energy threshold for head fractures. Because of the great variability of biological tissue of real skulls, we opted for a head model made from a polyurethane sphere filled with gelatin. Furthermore, we decided to investigate two opposite situations: A fixed configuration where a model was placed on a rigid surface and a (quasi) free boundary configuration where the head model was held at a force of 5 N compensating for gravity. For both configurations, we determined the acceleration signal of the impactor, the force, and the energy threshold for head fracture. It turned out that the fracture forces for both configurations were the same whereas the energy threshold was 11.0 J for the fixed and 13.6 J for the free boundary. The difference seems to be negligible if compared to the effect of varying structural mechanical properties of real human heads. This means that in a forensic case, the two situations most probably cannot be distinguished. To investigate the influence of the impactor mass, we developed a mathematical model and fitted the experimental data. As a result, we found that in the free configuration, a larger mass increases the energy threshold for head fracture. So that in principle, the two configurations are distinguishable. [ABSTRACT FROM AUTHOR]

Our institute of Legal Medicine was asked to examine a 27-year-old patient admitted to the neurosurgical department after a non-fatal accident (non-observed fall from height) at a construction site. Forensic advice was needed because of unexplainable injuries. By example of this case of a near-to-impalement, we would like to highlight an unusual, clinically frequently forgotten, and forensically thus far not discussed type of skull fracture with outward dislocation of bone fragment(s). These so-called compound elevated fractures of the skull are described occasionally in, mainly neurosurgical, case reports. Knowing its entity and its pathomechanism may be of forensic interest, particularly in order of reconstruction purpose. This article provides a brief review of the literature with special regard to the pathomechanism. In addition, it demonstrates the possible pitfall of computed tomography, or more specifically, the 3D reconstruction. To our knowledge, this is the first forensic report describing this kind of fracture. [ABSTRACT FROM AUTHOR]

Suicides committed by intraorally placed firecrackers are rare events. Given to the use of more powerful components such as flash powder recently, some firecrackers may cause massive life-threatening injuries in case of such misuse. Innocuous black powder firecrackers are subject to national explosives legislation and only have the potential to cause harmless injuries restricted to the soft tissue. We here report two cases of suicide committed by an intraoral placement of firecrackers, resulting in similar patterns of skull injury. As it was first unknown whether black powder firecrackers can potentially cause serious skull injury, we compared the potential of destruction using black powder and flash powder firecrackers in a standardized skull simulant model (Synbone, Malans, Switzerland). This was the first experiment to date simulating the impacts resulting from an intraoral burst in a skull simulant model. The intraoral burst of a 'D-Böller' (an example of one of the most powerful black powder firecrackers in Germany) did not lead to any injuries of the osseous skull. In contrast, the 'La Bomba' (an example of the weakest known flash powder firecrackers) caused complex fractures of both the viscero- and neurocranium. The results obtained from this experimental study indicate that black powder firecrackers are less likely to cause severe injuries as a consequence of intraoral explosions, whereas flash powder-based crackers may lead to massive life-threatening craniofacial destructions and potentially death. [ABSTRACT FROM AUTHOR]

Reports on penetrating ballistic head injuries in the literature are dominated by case studies of suicides; the penetrating ammunition usually being .22 rimfire or shotgun. The dominating cause of injuries in modern warfare is fragmentation and hence, this is the primary threat that military helmets protect the brain from. When helmets are perforated, this is usually by bullets. In combat, 20 % of penetrating injuries occur to the head and its wounding accounts for 50 % of combat deaths. A number of head simulants are described in the academic literature, in ballistic test methods for helmets (including measurement of behind helmet blunt trauma, BHBT) and in the 'open' and 'closed' government literature of several nations. The majority of these models are not anatomically correct and are not assessed with high-velocity rifle ammunition. In this article, an anatomically correct 'skull' (manufactured from polyurethane) and 'brain' (manufactured from 10 %, by mass, gelatine) model for use in military wound ballistic studies is described. Filling the cranium completely with gelatine resulted in a similar 'skull' fracture pattern as an anatomically correct 'brain' combined with a representation of cerebrospinal fluid. In particular, posterior cranial fossa and occipital fractures and brain ejection were observed. This pattern of injury compared favourably to reported case studies of actual incidents in the literature. [ABSTRACT FROM AUTHOR]

Post-mortem examination is often relied upon in order to determine whether a suspicious death was natural, accidental, suicidal or homicidal. However, in many cases the mechanism by which a single injury has been inflicted cannot be determined with certainty based on pathological examination alone. Furthermore the current method of assessing applied force relating to injury is restricted to an arbitrary and subjective scale (mild, moderate, considerable, or severe). This study investigates the pathophysiological nature of head injuries caused by blunt force trauma, specifically in relation to the incidence and formation of a laceration. An experimental model was devised to assess the force required to cause damage to the scalp and underlying skull of porcine specimens following a single fronto-parietal impact. This was achieved using a drop tower equipped with adapted instrumentation for data acquisition. The applied force and implement used could be correlated with resultant injuries and as such aid pathological investigation in the differentiation between falls and blows. Experimentation revealed prevalent patterns of injury specific to the reconstructed mechanism involved. It was found that the minimum force for the occurrence of a laceration was 4,000 N. [ABSTRACT FROM AUTHOR]

In shooting crimes, ballistics tests are often recommended in order to reproduce the wound characteristics of the involved persons. For this purpose, several "simulants" can be used. However, despite the efforts in the research of "surrogates" in the field of forensic ballistic, the development of synthetic models needs still to be improved through a validation process based on specific real caseworks. This study has been triggered by the findings observed during the autopsy performed on two victims killed in the same shooting incident, with similar wounding characteristics; namely two retained head shots with ricochet against the interior wall of the skull; both projectiles have been recovered during the autopsies after migration in the brain parenchyma. The thickness of the different tissues and structures along the bullets trajectories as well as the incident angles between the bullets paths and the skull walls have been measured and reproduced during the assemblage of the synthetic head models. Two different types of models ("open shape" and "spherical") have been assembled using leather, polyurethane and gelatine to simulate respectively skin, bone and soft tissues. Six shots have been performed in total. The results of the models have been compared to the findings of post-mortem computed tomography (PMCT) and the autopsy findings.Out of the six shots, two perforated the models and four were retained. When the projectile was retained, the use of both models allowed reproducing the wounds characteristics observed on both victims in terms of penetration and ricochet behaviour. However, the projectiles recovered from the models showed less deformation than the bullets collected during the autopsies. The "open shape" model allowed a better controlling on the shooting parameters than the "spherical" model. Finally, the difference in bullet deformation could be caused by the choice of the bone simulant, which might under-represent either the strength or the density of the human bone. In our opinion, it would be worth to develop a new, more representative material for ballistic which simulates the human bone., (© 2021. The Author(s).)

This paper describes the variety of information that a tool mark analysis on human tissue can provide based on a case of multiple sharp violence. The perpetrator attacked the victim with a sharp-edged weapon against the head, leaving several deep wounds on the back of the skull bone. Three of those marks on the skull bone could be used for a forensic tool mark examination. Silicone casts of the marks were compared by light microscopy with casts of test marks of Japanese katana swords found at the crime scene. One of the swords could be identified as the one responsible for the marks. In addition, the marks and the test marks were scanned in 3D and examined in a visual on-screen comparison confirming the results from the light microscopic examination. Furthermore, a mathematical approach in which the signatures of the marks from the skull bone and the test marks from the sword were compared by cross correlation confirms those findings. In addition, the aforementioned results were used to determine the orientation of the sword in relation to the cranial bone at the time of the respective impact.

Timing of cranial trauma is challenging in forensic cases and literature on the subject is scarce. This study analysed the macroscopic fracture patterns of perimortem cranial fractures and compared them to experimentally reproduced cranial fractures on dry human craniums. The results showed nine traits associated with fresh cranial fractures: undulated margin, flake defects, peels with peel defects, fissures, crushed margins, bridge, bone scales and beveling. All the traits appear on the outer table or on the inner table of the cranium. Although not all characteristics must be present at the same time in all cranial fractures, they do define a new perimortem fracture pattern. Statistical analyses showed that six of these traits (undulated margins, flake defects, crushed margins, bone scales, fissures and peels) are distinctly related with perimortem (fresh) bone conditions. Considering the most discriminant perimortem traits, a decision-making algorithm is developed as a probabilistic approach to distinguish peri- from postmortem cranial fractures with an accuracy of 87%. This algorithm allows the forensic practitioner to incorporate more confidence during cranial trauma evaluation.

Existing literature on the relationship between bullet diameter and bullet defect diameter in the human calvarium is summarized and discussed. The hypothesis, derived from the literature, that bullet deformation influences bullet defect diameter was studied in a small controlled experiment. The mean defect size caused by non-deforming projectiles was found to be smaller than the mean defect size caused by deforming projectiles of equal original mass and size. The p value of the difference between the two means, measured in two different ways, was found to be 0.002 for both in a Mann-Whitney U test and was significant if the confidence level is set at 5%.

A single gunshot (or multiple) does (do) not necessarily lead to immediate loss of consciousness or rapid neurological deficits, so the victim may be able to repeatedly pull the trigger before achieving the lethal effect. Despite multiple gunshot wounds can lead to the suspicious participation of other person to the death of the victim, in the medico-legal literature suicides with multiple gunshot wounds are reported, demonstrating the ability of the victim to act after two or more gunshots. In this case, a 47-years-old man was found dead in a pool of blood in the kitchen of his house. According to findings and analysis, the victim modified a single-shot, pneumatic toy gun branded "Condor" Cal. 7 mm (a gun that is made mainly with "ZAMAK" zinc-based alloy, designed to shoot one soft-polymer bullet at a time, with an initial kinetic energy lower than 1 Joule) into an improvised firearm weapon. With this gun, the victim achieved shooting of two bullets into his head, both entering from the right temporal region of his head, with one stopped in the left occipital lobe and the other one in the left temporal lobe. His death was caused by cranium-meningo-encephalic gunshot wounds. The conditions supporting the hypothesis that the victim was able to fire two shots to his head before the onset of incapacitation (the type of bullets used, the location of injuries and their consequences) and the characteristics that typically allow to distinguish the manner of death (suicide vs homicide) were evaluated. Based on all the collected elements, it was possible to confirm that suicide was the manner of death. This case underlines the importance of evaluating all available elements (post-mortem imaging, autopsy and toxicological findings, ballistics and neuropathological evaluations) to distinguish suicide from homicide and to prevent incorrect conclusions.

Six synthetic head models wearing ballistic protective helmets were used to recreate two military combat-related shooting incidents (three per incident, designated 'Incident 1' and 'Incident 2'). Data on the events including engagement distances, weapon and ammunition types was collated by the Defence Science and Technology Laboratory. The models were shot with 7.62 × 39 mm ammunition downloaded to mean impact velocities of 581 m/s (SD 3.5 m/s) and 418 m/s (SD 8 m/s), respectively, to simulate the engagement distances. The damage to the models was assessed using CT imaging and dissection by a forensic pathologist experienced in reviewing military gunshot wounds. The helmets were examined by an MoD engineer experienced in ballistic incident analysis. Damage to the helmets was consistent with that seen in real incidents. Fracture patterns and CT imaging on two of the models for Incident 1 (a frontal impact) were congruent with the actual incident being modelled. The results for Incident 2 (a temporoparietal impact) produced realistic simulations of tangential gunshot injury but were less representative of the scenario being modelled. Other aspects of the wounds produced also exhibited differences. Further work is ongoing to develop the models for greater ballistic injury fidelity.

SYNBONE® spheres were impacted with 7.62 × 39 mm mild steel core ammunition at a mean impact velocity of 654 m/s, SD 7 m/s, to simulate engagement distances of around 50-100 m. The wounds and fracture patterns were assessed by two forensic pathologists familiar with military cranial injury. The overall fracture pattern was assessed as being too comminuted when compared with actual injury. This suggests the SYNBONE® spheres have less utility for simulating military injury than other purposes described in the literature.

From time to time, severe or fatal injuries caused by small caliber air rifle projectiles are seen. In forensic sciences, the theoretical wounding potential of these weapons and projectiles is widely known. Usually, shots against the skull were reported and, in these cases, penetrating the eyes or thin bone layers of the temporal region. Amongst a huge number of different projectiles available for air guns, sub-caliber 4.4-mm (.173) caliber steel ball projectiles were used in an unusual suicide case. This case led to fundamental questions concerning wound ballistics. An 82-year-old man shot once against his right temporal region and twice into his mouth with a 4.5-mm (.177) caliber air rifle. Because of the exceptionally deep penetration of the base of the skull and the use of spherical-shaped sub-caliber air rifle projectiles, terminal ballistic features were analyzed and compared to results published in forensic literature. Test shots using the same weapon and similar projectiles were fired into ballistic gelatin to measure and calculate basic wound ballistic variables of cal. 4.4-mm (.173) steel balls. In comparison, further test shots with cal. 4.5-mm (.177) steel balls BB (ball bearing), flat-headed and pointed air rifle pellets ("diabolos") were carried out. The theoretical penetration depth in solid bone was calculated with 36.4 mm, and test shots in gelatin from hard contact produced an on-average wound track of 120 mm underlining the potential wounding effect. Furthermore, spherical projectiles could roll back and forth within the barrel, and an air cushion between projectile and breechblock can reduce muzzle velocity by more than half, explaining the retained missile in the temporal region.

Methodologies that improve estimation of caliber from cranial bone defects are necessary to meet the ever increasing admissibility standards. The relationship between caliber, wound diameter, and bone mineral density (BMD) was examined. The formation of the permanent cavity is influenced by bullet yaw, velocity, distance, and tissue properties. The hypothesis was that including BMD, wound diameter could be explained by differences in caliber. The sample consists of 68 autopsy sections and 101 specimens from Phelps (1898). A subsample of 18 was scanned using dual energy x-ray absorptiometry (DEXA) for BMD measurement to test whether an increase in BMD affects wound diameter. Pearson product-moment correlations of the subsample indicate the strongest correlation is between BMD and minimum diameter (r = 0.7101), followed by a correlation between minimum diameter and caliber (r = 0.6854). Despite the previous use of thickness as a proxy for BMD, no correlation was found between BMD and thickness (r = 0.0143). A multivariate analysis of variance (MANOVA) detected a significant influence of BMD and minimum diameter on caliber size (Prob > F = 0.0003). The logistic regression shows that caliber can be estimated from minimum diameter. Using the subsample, the results show that the inclusion of BMD strengthens the model for estimating caliber from entrance gunshot defects.

Since the 1960s, predictive human head impact indices have been developed to help the investigation of causation of human head injury. Finite-element models (FEM) can provide interesting tools for the forensic scientists when various human head injury mechanisms need to be evaluated. Human head FEMs are mainly used for car crash evaluations and are not in common use in forensic science. Recent technological progress has resulted in creating more simple tools, which will certainly help to consider the use of FEM in routine forensic practice in the coming years. This paper reviews the main FEMs developed and focuses on the models which can be used as predictive tools. Their possible applications in forensic medicine are discussed.

We performed an autopsy on a 3-month-old baby boy who had only one area severe and extensive wound to his head and face. Three unrelated miniature dachshunds were in the house. After our investigation, we were able to confirm that the wound had in fact been caused by a dog attack, and we were able to identify the offending dog among the three dogs using both human and canine short tandem repeat obtained from samples taken from the suspected dog and from the scene of the attack.

Contact gunshot wounds are usually characterized by a muzzle imprint, a powder cavity ("pocket"), the presence of carboxyhemoglobin and often also stellate tears of the skin radiating from the bullet entrance hole. In shots to the cerebral cranium an additional sign may be observed around the bone defect: the periosteum is detached and reflected with soot on the underside. The frequency and possible causes of these periosteal findings are discussed on the basis of 68 contact gunshot wounds from forensic autopsy material and experimental shots fired against the frontal bone of a slaughtered calf.

In 1945 a 6-year-old girl received a tangential gunshot injury to the left posterior inferior skull. After hospitalisation because of septicemia she was unable to walk for several months. Since 1967 she had been repeatedly applying for compensation because of pseudoneurasthenia and residual ataxia and many medical examinations were performed including X-ray, CT and MRI. Although certain objective findings (e. g. cerebellar atrophy) could be verified, a causal connection between the gunshot injury and the clinical findings could not be established. Therefore previous investigators concluded on a vascular origin of the disease. During the present re-examination of the patient, the authors found patch-like scars at the left posterior inferior skull base and behind the left ear, a cord-like scar formation in the subcutaneous tissue, connecting both skin scars, a gutter-like defect in the left occipital base of the skull and an indention of the left mastoid process, both again in line between the skin scars and a large defect of the left cerebellar hemisphere. It could be concluded with certainty that the anatomical findings and the clicinal symptoms were the direct result of a gunshot injury. Previous investigations had failed because of deficient investigations and techniques. In addition to an anatomical reconstruction, three dimensional reconstructions from CT scans proved most helpful.

A man committed suicide in his bathroom using a small pocket knife. At the autopsy a total of 92 stab wounds on the forehead, in both temples, the anterior aspect of the neck, the back of the neck, the chest and the sides of the trunk were found. In addition, repeated stabbing had caused a large soft tissue defect on the forehead. The frontal bone showed 3 perforations but no brain injury was present and two ribs were severed in the bony part, one of which carried a star-like pattern from repeated stabbing. No major vessels were injured and the cause of death was exsanguination after a considerable survival time. The large number of stab wounds, the perforation of bone and some injury sites, especially the head and back of the neck, are extraordinary findings in suicides which were probably favoured by insufficient anatomical knowledge and the use of a short-bladed knife. A psychiatric history could not be verified.

A case of homicide is described where the body of a young woman was found in the countryside in a state of advanced decomposition. The autopsy revealed that almost all the internal organs were missing, but not due to putrefaction. The thoracic cavity was opened in the professional manner normally used during an autopsy. The remains of the small intestine were tied with strands of hair braided into a thin cord.

The autopsy findings of intensive gunshot residues at the exit wound after a gunshot wound in the head led to an experimental investigation to clarify the mode of origin and intensity of these gunshot residues on the inner surface of the exit wound. For this purpose a simple skull/brain model was prepared. The results of the examination showed that with weapons of the same calibre distinct gunshot residues should be expected at the exit wound.