Examination of Hacking and Blunt Force Skeletal Trauma

Hacking trauma is prevalent in forensic cases involving genocide and dismemberment, but research into the identification of this type of trauma is lacking. The present study examines characteristics of hacking and blunt force skeletal trauma in order to determine if there is a point at which blunt force trauma becomes distinguishable from hacking trauma. Ten implements with a range of blade angles (i.e., the striking surface of the implement) were used in conjunction with a controlled-force hacking device to impact 100 limb bones of white-tailed deer (Odocoileus virginianus). Observations of the trauma included the occurrence and degree of fragmentation, the entrance widths of the impacts, and composite scores of six hacking characteristics, especially the distinctive V-shaped kerf. ANOVA tests and regression analyses were used to assess the relationships between these characteristics and the blade angles. A significant relationship (p-value = 0.011) was found between the composite hacking scores and the blade angles, indicating that blunt force and hacking trauma can be distinguished. The entrance widths of the impacts exhibited a significant relationship with the blade angles (p-value = 0.037). There was also a significant relationship between the visibility of a V-shaped kerf in the bones (p-value = 0.003), with visibility decreasing around the 60° blade angle. These data should assist in establishing guidelines to differentiate hacking and blunt force skeletal trauma in cases where the implement is on a spectrum between sharp and blunt.     

Blunt force cranial trauma in the Cambodian killing fields

In this paper we present a unique pattern of blunt force cranial trauma that was observed in 10 of a sample of 85 crania from a Cambodian skeletal collection comprised of Khmer Rouge victims. Initial examination of the trauma, which presents as substantial damage to the occipital with fractures extending to the cranial base, suggested the pattern was classifiable as a basilar or ring fracture. However, further investigation, including trauma analysis and historical research, revealed that this fracture type is distinctive from basilar and ring fractures. Historical data indicate that a particular execution method was the likely source of the trauma. Recognition of this trauma pattern is significant because it exemplifies the distinct fracture configuration resulting from an apparently categorical and methodical execution technique. Identification of this fracture type could potentially assist forensic investigators in the recognition of specific methods of murder or execution.     

Assessing Impact Direction in 3‐point Bending of Human Femora: Incomplete Butterfly Fractures and Fracture Surfaces,,

Current literature associates bending failure with butterfly fracture, in which fracture initiates transversely at the tensile surface of a bent bone and branches as it propagates toward the impact surface. The orientation of the resulting wedge fragment is often considered diagnostic of impact direction. However, experimental studies indicate bending does not always produce complete butterfly fractures or produces wedge fragments variably in tension or compression, precluding their use in interpreting directionality. This study reports results of experimental 3‐point bending tests on thirteen unembalmed human femora. Complete fracture patterns varied following bending failure, but incomplete fractures and fracture surface characteristics were observed in all impacted specimens. A flat, billowy fracture surface was observed in tension, while jagged, angular peaks were observed in compression. Impact direction was accurately reconstructed using incomplete tension wedge butterfly fractures and tension and compression fracture surface criteria in all thirteen specimens.     

Cardiac Injuries Caused by Blunt Trauma: An Autopsy Based Assessment of the Injury Pattern

Abstract:  Nonpenetrating chest trauma with injury to the heart and aorta has become increasingly common, particularly as a result of rapid deceleration in high-speed vehicular accidents, over the past 2–3 decades. The high mortality rate of cardiac injuries and possible late onset complications make blunt cardiac injuries an important challenging point for legal medicine. One hundred and ninety cases with blunt cardiac injuries in a period of 3 years were analyzed retrospectively in terms of patterns of cardiac injury, survival times, and demographic profiles of the cases in this study.     

Dissecting Thoracic Aortic Hematoma Masquerading as Blunt Force Injury of the Neck

Discoloration of the skin of the anterior and lateral neck may raise suspicion for blunt force injury, particularly cervical compression, in an unwitnessed death. We present a case of an elderly woman with an unwitnessed death at home which highlights an external examination finding of blue/purple discoloration of the skin of the neck and links this finding with those from internal examination at autopsy. Pertinent negatives include absence of conjunctival and mucosal petechiae, absence of cutaneous abrasions of the neck, and absence of contusions of the anterior neck musculature. This case illustrates a natural disease entity, spontaneous dissection of a thoracic aortic hematoma, masquerading as blunt force injury externally and highlights the importance of having an appropriate index of suspicion when triaging jurisdictional cases for postmortem examination to accurately determine cause and manner of death.     

Patterns of Trauma Induced by Motorboat and Ferry Propellers as Illustrated by Three Known Cases from Rhode Island*

Abstract: Understanding patterns of trauma is important to determining cause and manner of death. A thorough evaluation of taphonomy, trauma, and bone fracture mechanisms is necessary to reconstruct the circumstances of the death. This study examines the skeletal trauma caused by boat propeller strikes in terms of wound characteristics and location based on three cases from Rhode Island. These case studies review the traumatic characteristics caused by propeller injuries and highlight the anatomic regions most likely to sustain skeletal trauma. With this information, investigators may be able to identify propeller trauma even in severely decomposed remains. The discussion of boat propeller trauma also raises issues regarding how forensic anthropologists and forensic pathologists classify trauma (specifically blunt force vs. sharp) and highlights semantic issues arising in trauma classification. The study also discusses why these propeller cases should be classified as blunt trauma rather than sharp or chop/hack trauma. Ultimately, the authors urge consistency and communication between pathologist and forensic anthropologists performing trauma analyses.     

Characterization and Comparison of Injuries Caused by Accidental and Non‐accidental Blunt Force Trauma in Dogs and Cats

Motor vehicle accidents (MVA) are often difficult to distinguish from non‐accidental injury (NAI). This retrospective case–control study compared animals with known MVA trauma against those with known NAI. Medical records of 426 dogs and cats treated after MVA and 50 after NAI were evaluated. Injuries significantly associated with MVA were pelvic fractures, pneumothorax, pulmonary contusion, abrasions, and degloving wounds. Injuries associated with NAI were fractures of the skull, teeth, vertebrae, and ribs, scleral hemorrhage, damage to claws, and evidence of older fractures. Odds ratios are reported for these injuries. MVA rib fractures were found to occur in clusters on one side of the body, with cranial ribs more likely to fracture, while NAI rib fractures were found to occur bilaterally with no cranial–caudal pattern. Establishing evidence‐based patterns of injury may help clinicians differentiate causes of trauma and may aid in the documentation and prosecution of animal abuse.     

The Accuracy and Applicability of 3D Modeling and Printing Blunt Force Cranial Injuries

The purpose of this study was to determine the factors affecting the accuracy of 3D models and 3D prints of cranial blunt force trauma, to evaluate the applicability and limitations of modeling such injuries. Three types of cranial blunt force lesions were documented (hinge, depressed, and comminuted) using three forms of surface scanning (laser, structured light scanner, and photogrammetry) at two different quality settings (standard and high). 3D printed models of the lesions were produced using two different materials (a gypsum‐like composite powder called VisiJet^® PXL and an acrylic engineered composite plastic called VisiJet^® M3 in crystal colour). The results of these analyzes indicate the prints in this study exhibit some statistically significant differences from the actual bone lesions, but details of the lesions can be reproduced to within 2 mm accuracy.     

An Assessment of the Skeletal Fracture Patterns Resulting from Fatal High (˃3 m) Free Falls

The injury patterns resulting from fatal high (?3 m) free falls have previously been documented in clinical and medico‐legal contexts; however, details relating specifically to the skeletal blunt force trauma (BFT) have been limited. This study aimed to augment what is known of the skeletal fracture patterns resulting from fatal high free falls. Skeletal trauma was analyzed from full‐body postmortem computed tomography scans of 95 individuals who died following a high free fall. Fracture patterns were documented using the five general anatomical regions, axial and appendicular regions, and postcranial unilateral and bilateral regions. Patterns were analyzed in the context of the extrinsic and intrinsic variables that may influence fractures using multiple logistic regression. Fracture patterns involved all aspects of the skeleton, with 98.9% exhibiting polytrauma, and were influenced primarily by the height fallen, manner of death, and landing surface. This improved understanding of fracture patterns will augment anthropological interpretations of the mechanism of BFT in cases of suspected high falls.     

Skeletal Trauma Resulting From Fatal Low (≤3 m) Free Falls: An Analysis of Fracture Patterns and Morphologies

The skeletal trauma resulting from fatal low (≤3 m) free falls is poorly researched and understood by forensic practitioners. The aim of this study was to identify the types of skeletal trauma resulting from low falls through investigating fracture patterns and morphologies. Skeletal trauma was analyzed using full‐body postmortem computed tomography scans of 145 individuals who died from a low free fall. Trauma was then contextualized to the variables that influence how a person falls using multiple logistic regression. Results showed fracture patterning primarily involved the axial skeleton and that there were a number of patterns significantly associated with the height fallen, pre‐existing health conditions, and age. Analysis of fracture morphologies showed 108 possible fracture types, six of which were significantly associated with the height fallen. Understanding the skeletal trauma characteristic of low free falls will further inform anthropological interpretations of trauma in cases where a fall may be considered the possible mechanism.     

Discrimination of Falls and Blows in Blunt Head Trauma: A Multi‐Criteria Approach

Abstract: In the discrimination of falls versus blows, the hat brim line (HBL) rule is mentioned in several textbooks as the most useful single criterion. Recent studies, however, have found that the HBL rule is only moderately valid and that its use on its own is not recommended. The purpose of this 6‐year retrospective study was to find additional individually useful criteria in the distinction of falls from blows. Overall, the following criteria were found to point toward blows: more than three lacerations, laceration length of 7 cm or more, comminuted or depressed calvarial fractures, lacerations or fractures located above the HBL, left‐side lateralization of lacerations or fractures, more than four facial contusions or lacerations, presence of ear lacerations, presence of facial fractures, and presence of postcranial osseous and/or visceral trauma. Based on the most discriminating criteria, a decision tree was constructed to be potentially applicable to future cases.     

Blast Injury and the Human Skeleton: An Important Emerging Aspect of Conflict‐Related Trauma

Recent decades have seen an accelerating trend in warfare whereby a growing proportion of conflict‐related deaths have been caused by explosions. Analysis of blast injury features little in anthropological literature. We present a review of clinical literature that includes prevalence of injury to anatomical regions and potential indicators of blast injury which can be used by forensic anthropologists. This includes high prevalence of extremity (22.8–91.2%) and facial (19.6–40%) injury in combat contexts, lower limb fractures (19–74.3%) in suicide bombing, traumatic amputation (3–43%) and diffuse fracture patterns in terrorist bombings. Potential indicators of blast trauma include blowout fractures in sinus cavities from blast overpressure, transverse mandibular fractures, and visceral surface rib fractures. Ability to recognize blast trauma and distinguish it in the skeleton is of importance in investigations and judicial proceedings relating to war crimes, terrorism, and human rights violations and likely to become increasingly crucial to forensic anthropology knowledge.     

Comparing Known and Reconstructed Circumstances of Death Involving a Blunt Force Trauma Mechanism through a Retrospective Analysis of 21 Skeletonized Individuals

Little is known about to what extent the events surrounding death can be reliably reconstructed from blunt force trauma analysis alone. In this study, we reconstruct circumstances of death from a blind blunt force trauma analysis using a sample of 21 individuals of known death circumstances, obtained from two identified skeletal collections in Portugal. Fresh versus dry bone trauma and probable mechanism of fracture production were identified. The overall pattern of injuries was then used to reconstruct the most likely circumstances of death. Results show an agreement between the proposed and the reported circumstances for 13 individuals (68.4%), disagreement for 3 (15.8%), and similarity in 3 cases (15.8%). Although the significant amount of agreement highlights the potential of trauma analysis, the cases with disagreement draw attention to the pitfalls and shortcomings of attempting to reconstruct the death circumstances from skeletal trauma analysis alone.     

Taphonomic changes to blunt force trauma: a preliminary study

This study examines the effects of taphonomic processes on blunt force trauma (BFT) through an experimental study involving pig heads. Of particular concern is the possibility that taphonomic changes can create pseudo-trauma and/or conceal evidence of actual trauma. BFT was inflicted on 10 pig skulls using a hammer. The skulls were subsequently exposed to the environment for 12 months. Seven taphonomic changes were evaluated: the freeze-thaw cycle; rodent gnawing; carnivore scavenging; presence/weight of soil; presence/weight of rain and snow; movement/displacement of bones; and discoloration due to sun bleaching and grass staining. Taphonomic effects varied between cancellous, compact, fresh, and degreased bone. Freezing and thawing, exposure to rain and snow, movement of the skulls, and soil erosion altered and, in some cases disguised, pre-existing trauma. Rodent and carnivore activity did not obliterate evidence of BFT. Recommendations for evaluating BFT on remains affected by taphonomic processes are presented. As each taphonomic process outlined by this study has the potential to disguise antemortem injury, the authors propose that one must carefully examine large, circular openings in the skull that may represent the remnant evidence of BFT.     

Discrimination of Falls and Blows in Blunt Head Trauma: Assessment of Predictability Through Combined Criteria*

Abstract: The discrimination of falls from homicidal blows in blunt head injuries is a common but difficult problem in both forensic anthropology and pathology. Three criteria have been previously proposed for this distinction: the hat brim line rule, side lateralization of fractures, and number of lacerations. The aim of the present study was to achieve a better distinction rate by combining those criteria and assess the predictability of these combined criteria tools. Over a 6‐year period, a total of 114 cases (92 males and 22 females) were studied: 21 cases of downstairs falls, 29 cases of falls from one’s own height, and 64 cases of head trauma by a blunt weapon. The results revealed predictability rates varying from 62.5 to 83.3% for criteria pointing towards a fall. As for combined criteria in favor of a blow, the assumption was accurate in all cases (100%).     

Patterns of trauma in conflict victims from Timor Leste

Understanding population-level trauma patterns has implications for the recognition of war crimes and crimes against humanity. Trauma data were abstracted from autopsy and anthropology reports for 105 victims from the 1999 conflict in Timor Leste. A significant number of individuals displayed no evidence of injury. No trauma was found in 25% of the sample, while a further 5% had only minor, nonlethal wounds. Where trauma was evident, sharp force injuries were most common (35%), followed by gunshot (20%) and blunt force (13.33%). Timorese frequencies of trauma differ significantly from percentages found in prior reports of mass killings from Cambodia, Bosnia, Croatia, and Afghanistan but closely resemble reported trauma patterns in Rwanda. Decomposition and percentage of body recovered were shown to have a significant impact on the presence/absence of trauma. Complete, fleshed remains were 10.4 times more likely than skeletal remains to have evidence of major or lethal trauma.     

Death Due to Isolated Jejunal Tear Following Blunt Abdominal Trauma

Small intestinal injury following blunt abdominal trauma has been widely reported. Isolated jejunal tear which is caused by blunt abdominal trauma is rare and is most often seen in road traffic accidents. Here, we report a case of isolated jejunal tear in a 24‐year‐old male truck driver. He was admitted to a tertiary care hospital in a South Indian Metropolitan city with complaints of acute abdominal pain and tiredness following alleged accidental blunt trauma sustained to abdomen due to steering wheel impact. An isolated jejunal tear and adjacent mesenteric contusion and tear were missed by the treating physician even after preliminary investigations, and thus, the conservative management was instituted. The condition deteriorated gradually, and he succumbed to death. The autopsy revealed transverse tear of jejunum almost involving whole of its circumference on the antimesenteric border and peritonitis. Proper use of radio‐diagnostic techniques and timely undertaken explorative laparotomy would have saved the life.     

The Difficult Task of Assessing Perimortem and Postmortem Fractures on the Skeleton: A Blind Text on 210 Fractures of Known Origin

The distinction between perimortem and postmortem fractures is an important challenge for forensic anthropology. Such a crucial task is presently based on macro‐morphological criteria widely accepted in the scientific community. However, several limits affect these parameters which have not yet been investigated thoroughly. This study aims at highlighting the pitfalls and errors in evaluating perimortem or postmortem fractures. Two trained forensic anthropologists were asked to classify 210 fractures of known origin in four skeletons (three victims of blunt force trauma and one natural death) as perimortem, postmortem, or dubious, twice in 6 months in order to assess intraobserver error also. Results show large errors, ranging from 14.8 to 37% for perimortem fractures and from 5.5 to 14.8% for postmortem ones; more than 80% of errors concerned trabecular bone. This supports the need for more objective and reliable criteria for a correct assessment of peri‐ and postmortem bone fractures.     

The Forensic Implications of Amphetamine Intoxication in Cases of Inflicted Blunt Craniocerebral Trauma

The effects of D‐amphetamine on outcome after blunt craniocerebral trauma are characterized and the potential legal implications discussed. Traumatic brain injury (TBI) was induced under general anesthesia in adult, male Sprague Dawley rats using the impact acceleration model. At 10 min prior to injury, D‐amphetamine (5 mg/kg) or saline vehicle was administered subcutaneously; animals were subsequently assessed over a 7‐day period post‐trauma for motor outcome using a rotarod device. D‐amphetamine treated animals performed significantly better (p < 0.001; ANOVA) than vehicle treated controls on their motor assessment, suggesting that D‐amphetamine exposure prior to injury either is neuroprotective or enhances motor performance. It is possible, therefore, that an individual who has taken amphetamines may function at a better motor level after head trauma than one who has not been exposed to the drug. Future interpretations of the potential effects of amphetamines on TBI should include this possibility.     

Skull Fracture with Brain Expulsion in a One-Level Jumping-Fall

Abstract:  Here presented is the case of a one-level jumping-fall with extensive skull fractures and brain expulsion. The body was found on the basement floor at the foot of the stairs. At the autopsy, the skull was extensively fractured, with about half of the brain expulsed several feet away from the body. The cause of death was established as a craniocerebral trauma with brain expulsion. The circumstances and manner of death were still unclear at that time. A low fall seemed very unlikely considering the severity of the skull and brain damage. The police investigation clearly revealed that the man, in a paranoid psychotic state, attacked his wife with a knife and then was witnessed by his children to have hit his head several times with a hammer. Afterwards, they saw him running to the top of the basement stairs and jumping to the bottom of the stairs head first.