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1.
Int J Legal Med ; 138(5): 2157-2167, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38763927

ABSTRACT

In most experimental protocols, false starts are produced on dry bones obtained through a maceration process for anthropological analyses, for the sake of reproducibility. Although this allows for controlled experimental conditions, the absence of soft parts when experimentally creating false starts does not correspond to the real conditions of criminal dismemberment. The main objective of this study was to determine if the results of experimental work on the characteristics of false starts were valid under medico-legal conditions. In this experimental study, a hand saw (rip saw, wavy set, TPI 32) was used. 240 false starts were produced on human and pig bones. Randomly, the false starts were either produced on a dry bone or on a flesh bone. The criteria for microscopic analysis included the shape of the walls, the shape and visibility of striae on the floor, the shape of the profile, and the minimum width of the false start. On human bone, 100% of the false starts produced on a bone that had previously undergone a maceration process for anthropological analyses (dry bone) allowed the definition of all the blade characteristics. This was the case for 78.3% on bone in the presence of soft tissue (flesh bone). The striae on the floor of the false start are in some cases less visible with flesh bones, implying that it may be more difficult to conclude on the characteristics of a saw under medico-legal conditions.


Subject(s)
Bone and Bones , Corpse Dismemberment , Humans , Swine , Animals , Bone and Bones/pathology , Forensic Anthropology/methods
2.
Forensic Sci Med Pathol ; 19(4): 595-604, 2023 12.
Article in English | MEDLINE | ID: mdl-36735188

ABSTRACT

We report on a case of criminal dismemberment and attempted scalping of a homicide victim with a "Mohawk" haircut. Case findings are presented. A review of the literature was performed for scalping in its historical and cultural context and particularly in criminal dismemberment and mutilation: Historically, scalping was prevalent in many ancient cultures around the world, where scalps were taken as trophies or "proof of kill", much like shrunken heads, trophy skulls, and other artefacts. Scalping was particularly widespread in Northern America in the context of tribal warfare, both before and after colonization. The iconic "Mohawk" haircut is closely linked with scalping, as it was meant to taunt the enemy. In the modern forensic context, scalping constitutes a form of criminal mutilation. However, cases of criminal dismemberment and mutilation are rare in forensic casework. Our literature review revealed a low number of scalping in criminal dismemberment and mutilation cases. The documentation was overall poor. Positioning scalping within the classification of criminal mutilation and dismemberment was difficult. In literature, even though case numbers were small, the majority of "textbook scalping" cases were German. The presented case, to our best knowledge, is the first modern-day photo-documented case of (attempted) scalping, even more so of a person wearing a "Mohawk".


Subject(s)
Corpse Dismemberment , Criminals , Humans , Scalp , Homicide , Artifacts
3.
Int J Legal Med ; 135(4): 1627-1636, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33956198

ABSTRACT

The estimation of the postmortem interval (PMI) is of critical importance in forensic routine. The most frequently applied methods, however, are all restricted to specific time periods or must be excluded under certain circumstances. In the last years it has been shown that the analysis of muscle protein degradation has the potential to contribute to according delimitations in practice. In particular, upon biochemical analysis, the specific time points of degradation events provide reasonable markers for PMI delimitation. Nevertheless, considerable research is yet required to increase the understanding of protein decomposition and how it is affected by individual and environmental influencing factors. This is best investigated under standardized conditions, however, a considerate selection of proxies, regarding costs, effort, and expected outcome is required. Here, we use pigs to compare muscle protein decomposition in whole bodies and dismembered body parts (amputated hind limbs). Not only do experiments on body parts reduce the costs and allow easier handling in basic research, but also they aid to investigate the practical application of PMI estimation in dismembered body parts, or other extensive injuries, which are not unusual scenarios in crime investigation. Specifically, we investigated whether there are differences in the degradation rates of selected muscle proteins, sampled from dismembered legs and from hind limbs attached to whole pig bodies. Our results show distinct time-dependent degradation patterns of muscle proteins in a predictable manner regardless of sample origin. We are able to demonstrate that amputated hind limbs are suitable proxies for the analysis of muscle protein degradation, especially to investigate certain influencing factors and establish according standardized models.


Subject(s)
Models, Animal , Muscle Proteins/metabolism , Muscle, Skeletal/metabolism , Postmortem Changes , Proteolysis , Swine , Animals , Corpse Dismemberment
4.
Int J Legal Med ; 135(3): 801-815, 2021 May.
Article in English | MEDLINE | ID: mdl-33084995

ABSTRACT

During a homicide investigation in which fire has been used to reduce the size of the cadaver and conceal the evidence of injuries, the identification of perimortem trauma presents a challenge, in particular in cases when the perpetrator has dismembered the body followed by burning the remains. It is therefore important to understand the effects which heat causes on fresh bone. The aim of this paper is to perform a pilot study on the survival ratio of toolmarks in different anatomical regions associated with dismemberment, and a descriptive analysis of the variables that may potentially influence the post-burning survival and detection. To achieve this, three donated embalmed cadavers were used to simulate a case in which an attempted dismemberment and burning had occurred. Fifty-five pre-burning injuries were manually induced: 30 using a machete to inflict chopping trauma, and 25 with a serrated bread knife to inflict sharp force trauma, on the thigh, knee, ankle and wrist. The cadavers were cremated in a furnace at Madrid's Cementerio Sur and the burnt remains were analysed at the Laboratorio de Antropología y Odontología Forense of the Universidad Complutense de Madrid. Not all pre-burning injuries inflicted were visible after the cremation process; only 13% were detected in this experiment. Toolmarks can be masked, modified, destroyed or overlooked from the outset of the procedure due to several factors which influence the post-burning survival and detection of toolmarks and contribute to conceal the evidence of trauma. Additional research should be done to study further variables which affect the post-burning visibility of sharp force trauma.


Subject(s)
Bone and Bones/injuries , Corpse Dismemberment , Cremation , Wounds, Penetrating/pathology , Aged , Humans , Male , Middle Aged , Pilot Projects , Spain , Weapons
5.
Int J Legal Med ; 135(1): 193-205, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32474664

ABSTRACT

INTRODUCTION: The concealment of the body following a homicide undermines different moments of the forensic and medico-legal investigations. The aim of the present study is to provide an overview of the literature and the forensic casuistry of the Institute of Legal Medicine of Padova for analyzing and discussing diverse methodological approaches for the forensic pathologist dealing with covered-up homicides. MATERIAL AND METHODS: A literature review, updated until September 2019, was performed, and a literature pool of forensic cases was built. In-house cases were included by conducting a retrospective analysis of the forensic caseworks of Padova of the last 20 years. Data regarding epidemiology, methodology of assessment, methods of concealment, and answers to medico-legal issues were extracted for both data sets. RESULTS AND DISCUSSION: Seventy-eight papers were included in the literature review (78.2% being case reports or case series, 17% retrospective studies, and 6% experimental studies or reviews). Literature and in-house data sets consisted of 145 and 13 cases, respectively. Death scene investigation, radiology, toxicology, and additional analyses were performed in 20-54% of literature and 62-77% of in-house cases. Cover-up by multiple methods prevailed. Death was caused by head trauma in about 40% of cases (both data sets), strangulation in 21% of literature, and 7% of in-house cases, and was undetermined in 17% of literature and 7% of in-house cases. CONCLUSIONS: The methodology of ascertainment should be case-specific and based on a multidisciplinary and multimodal evaluation of all data, including those gained through novel radiological and/or analytical techniques.


Subject(s)
Cadaver , Homicide/statistics & numerical data , Age Distribution , Burial/statistics & numerical data , Corpse Dismemberment , Crime Victims/statistics & numerical data , Criminals/statistics & numerical data , Fires/statistics & numerical data , Forensic Medicine , Freezing , Humans , Immersion , Motivation , Retrospective Studies , Sex Distribution
6.
Am J Forensic Med Pathol ; 42(1): 73-76, 2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33074838

ABSTRACT

ABSTRACT: A case involving an adult dismembered body with myositis ossificans (MO) is described. A woman in her 20s was found dead in her cohabitants' room. The body had dismembered into 15 pieces. Computed tomography showed ectopic mineralization in the bilateral upper arms and thighs. On autopsy, the skin and soft tissue were in the process of adipocere formation. Darkened areas that appeared to be subcutaneous hemorrhage were distributed on the face, left chest, and back. Bilateral upper arms and thighs showed organized granulations adherent to underlying bone. Microscopically, these organized lesions represented mature bone tissue in the periphery, cartilage tissue in the middle layer, and fibrotic tissue in the central part. These were typical findings of MO. Myositis ossificans and subcutaneous hemorrhage seemed to be evidence of antemortem repetitive physical abuse. In cases of dismemberment, the absence of organs and parts of the body provide limitations to determining cause of death. In forensic fields, adult autopsy cases involving MO are rare. This is an unusual case in which MO revealed antemortem physical abuse despite dismemberment of the body.


Subject(s)
Corpse Dismemberment , Myositis Ossificans/pathology , Physical Abuse , Adult , Female , Humans , Humerus/diagnostic imaging , Humerus/pathology , Tomography, X-Ray Computed
7.
Int J Legal Med ; 134(2): 543-551, 2020 Mar.
Article in English | MEDLINE | ID: mdl-30758714

ABSTRACT

Postmortem dismemberment results from the use of sharp or sharp blunt instruments. Saws produce specific bone lesions, and the observation of certain saw mark features allows for the recognition of certain characteristics of the saw and its teeth. At autopsy, sections of the skull and other parts of the skeleton are usually achieved using an electrical oscillating autopsy saw. In cases of dismemberment, this autopsy saw may create additional marks to those produced by the criminal activity. In order to help the forensic pathologist to differentiate the two types of marks, this experimental study used a stereomicroscope to examine 130 experimental false starts produced on animal and human bones by an oscillating autopsy saw. A flagrant succession of narrow and wide aspects of the walls (in a "figure of 8" shape), with obvious oval bone islands and undulating striae are patterns typically left behind by oscillating autopsy saws, but the depth of the false starts plays an important role in the variation of the features. In particular, superficial false starts tend to be associated with larger kerf widths, straight walls, and longitudinal bone islands.


Subject(s)
Autopsy/instrumentation , Bone and Bones/injuries , Forensic Pathology , Animals , Corpse Dismemberment , Electrical Equipment and Supplies , Humans , Swine
8.
Int J Legal Med ; 134(2): 613-618, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31965235

ABSTRACT

Cases of criminal dismemberment are encountered in forensic pathology and forensic anthropology. Saw mark analysis aims to determine the type of saw that was used: hand saw versus electrical saw, crosscut and universal saw versus rip saw, size of the teeth ("teeth per inch" TPI), and set type. The goal of this study was to analyze using a stereomicroscope a series of 60 experimental false starts (30 lesions for each saw) produced on human bones by two different handsaws with a high TPI (15 and 32). The lesions caused by these high TPI saws have rarely been described in the forensic literature. Saw 2 (rip hacksaw with a 32 TPI and a wavy set) displayed classical features. In contrast, saw 1 (universal panel saw, TPI 15, alternating set) did not produce the expected characteristics: the minimum width of the kerf was weak, the kerf walls were straight, the striae were straight, and the kerf profile was very peculiar with a succession of peaks and dips that has not yet been described.


Subject(s)
Bone and Bones/injuries , Bone and Bones/pathology , Corpse Dismemberment , Forensic Pathology , Aged, 80 and over , Bone and Bones/diagnostic imaging , Equipment Design , France , Humans , Male , Microscopy
9.
Behav Sci Law ; 37(5): 589-601, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31393051

ABSTRACT

Little exists beyond medicolegal case reports on victim mutilation homicides, much less on those occurring in the context of sexual homicides. As limited information is available on sexual homicides that occurred in China, this study aims to explore the offending characteristics of sexual homicide offenders (SHOs) who mutilated their victims and to compare their modus operandi with non-mutilation sexual murderers. The offender, victim, and offense characteristics of 82 sexual homicide cases (i.e., 31 mutilation and 47 non-mutilation cases; 1988-2018), derived from police data of three regions and published case reports, were examined. In addition to the descriptive offender and victim characteristics of Chinese SHOs who performed victim body mutilation, findings indicate that offenders who mutilated their victims were more likely than those who did not mutilate the victim to have a previous sexual offense conviction. They were motivated primarily by sex and least motivated by financial gain. Victim abduction prior to the offense was more frequently reported in non-mutilation sexual murders. These findings may offer some insights for police who need to prioritize their investigative strategies in cases of sexual homicide with victim mutilation.


Subject(s)
Corpse Dismemberment , Homicide , Motivation , Sex Offenses , Adolescent , Adult , Aged , Aged, 80 and over , Case-Control Studies , Child , China , Crime , Crime Victims , Criminals , Female , Humans , Male , Middle Aged , Police , Sexual Behavior , Young Adult
10.
Forensic Sci Med Pathol ; 14(4): 568-573, 2018 12.
Article in English | MEDLINE | ID: mdl-29594832

ABSTRACT

On 30th March 1902 Police Constable George Doyle and Carnarvon Station manager Albert Dahlke were allegedly gunned down at Lethbridge's Pocket in Central Queensland. Approximately 90 kg of ash and burnt human remains with articles belonging to the two men were later found in saddle bags left at the scene on a police horse. Subsequently two local cattle and horse thieves, Patrick and James Kenniff, were convicted in the Queensland Supreme Court of the wilful murder of Constable Doyle. Patrick was executed by hanging on 12th January 1903 and James had his sentence reduced to life imprisonment with hard labor. A number of irregularities were subsequently raised about the trial including the use of a "special" jury and the reliability of evidence from a witness who did not actually see the event. Forensic issues to be explored involve the accuracy of the descriptions of the carbonized material, whether the remains were actually those of Doyle and Dahlke, and whether the victims were dismembered before burning, as was alleged by the prosecution.


Subject(s)
Forensic Medicine/history , Homicide/history , Bone and Bones , Corpse Dismemberment/history , Fires , History, 20th Century , Humans , Queensland
11.
Int J Legal Med ; 131(4): 1141-1147, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28116498

ABSTRACT

As a result of criminal activity, human bodies are sometimes dismembered and concealed within sealed, plastic waste sacks. Consequently, due to the inhibited ingress of insects and dismemberment, the rate of decomposition of the body parts within may be different to that of whole, exposed bodies. Correspondingly, once found, an estimation of the postmortem interval may be affected and lead to erroneous inferences. This study set out to determine whether insects were excluded and how rate of decomposition was affected inside such plastic sacks. The limbs, torsos and heads of 24 dismembered pigs were sealed using nylon cable ties within plastic garbage sacks, half of which were of a type claimed to repel insects. Using a body scoring scale to quantify decomposition, the body parts in the sacks were compared to those of ten exposed, whole pig carcasses. Insects were found to have entered both types of plastic sack. There was no difference in rate of decomposition in the two types of sack (F 1,65 = 1.78, p = 0.19), but this was considerably slower than those of whole carcasses (F 1,408 = 1453, p < 0.001), with heads showing the largest differences. As well as a slower decomposition, sacks resulted in formation of some adipocere tissue as a result of high humidity within. Based upon existing methods, postmortem intervals for body parts within sealed sacks would be significantly underestimated.


Subject(s)
Corpse Dismemberment , Plastics , Postmortem Changes , Animals , Coleoptera , Diptera , Feeding Behavior , Swine
12.
Int J Legal Med ; 131(5): 1313-1323, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28560543

ABSTRACT

This paper describes a new approach to determine characteristics of the implement used to inflict trauma which involves the histological analysis of exogenous particles. Based on Locard's principle "every contact leaves a trace," we decided to assess whether histological examination of bone and soft tissue around a penetrating injury (sharp force trauma) could provide evidence of the offending implement. Case reports and experimental studies have demonstrated the potential of cut mark features in bone to identify the causative implement and potentially assist in identifying the perpetrator. Scanning electron microscopy in combination with energy-dispersive X-ray spectrometry (SEM/EDS) have previously been reported to identify exogenous particles from various implements. In medical research, histological techniques are used to study the impact of foreign particles in tissues originating from implants. However, the routine use of histology in forensic medicine focuses on understanding type and timing of injuries. Based on three forensic cases, the results presented in this paper demonstrate that histology offers a cost-efficient and reliable means to detect foreign particles related to offending implement and/or to the environment where the victim was located. The interpretation of histological results was performed in conjunction with the macroscopic autopsy findings and anthropological analysis of bone samples.


Subject(s)
Bone and Bones/pathology , Corpse Dismemberment , Weapons , Wounds, Stab/pathology , Bone and Bones/injuries , Female , Forensic Pathology/methods , Humans , Male , Microscopy , Staining and Labeling , Young Adult
13.
Arch Med Sadowej Kryminol ; 66(4): 220-234, 2016.
Article in English | MEDLINE | ID: mdl-28677377

ABSTRACT

Aim of the study: To determine the circumstances which can be useful for offenders profiling in homicide cases with victim's body dismemberment. Material and methods: Study of all homicide cases with victim's corpse dismemberment examined in Krakow Department of Forensic Medicine over the last 50 years. Results: Within the past 50 years, a total number of 30 cases of homicides with dismembered bodies were examined in Krakow. 22 cases represent defensive mutilations performed by offender, 3 cases can be classified as offensive muti-lations and 3 cases represent aggressive mutilations - decapitation as a method of committing homicide. In this period the only 1 case of necrophilic mutilations was examined, when the body was dismembered without murder. In most cases the background of homicide was the family conflict, 6 was cause of mental illness of perpetrator and in 3 was sexual motive. Only in 3 cases (from 25 when the offender was known) perpetrator kill a stranger. In the other the offender belonged to the family or friends of the victim. In all cases where the perpetrator was determined, homicide and dismemberment was performed in his place of residence. The findings of the Police investigations indicate that in most cases homicides were not planned, occurred under the influence of emotion, only two have been previously scheduled. Conclusions: Homicides with corpses dismemberment usually are committed by offenders who is in close relationship with victim (family or friend). Dismemberment is almost always performed in the same place as murder - home of perpetrator. This type of homicide usually is not planned.


Subject(s)
Corpse Dismemberment , Forensic Medicine , Homicide/statistics & numerical data , Wounds and Injuries/pathology , Cause of Death , Crime Victims/statistics & numerical data , Decapitation , Female , Humans , Male , Poland
14.
Soud Lek ; 59(1): 7-9, 2014.
Article in English | MEDLINE | ID: mdl-24625020

ABSTRACT

We present the case of complete post-mortem decapitation of a 43 years old man killed by gunshots discharged from a distance of 40 - 50 cm. The corpse was left in the courtyard of his isolated carpentry and a mongrel dog lived in that courtyard, maybe attracted by the blood gushed from the wound, got a depredation of the corpse till the complete decapitation and the removal of all intrathoracic organs. The action of the dog was completed by the rats and mice that lived in the place. The case is not rare and sometimes the alteration of the features of the corpse makes it impossible for the investigators, to objectify any other signs of criminal nature.


Subject(s)
Bites and Stings/pathology , Corpse Dismemberment , Decapitation/etiology , Wounds, Gunshot/pathology , Adult , Animals , Decapitation/pathology , Dogs , Fatal Outcome , Forensic Pathology , Humans , Male , Mice , Rats
15.
Sud Med Ekspert ; 57(4): 34-9, 2014.
Article in Russian | MEDLINE | ID: mdl-25764863

ABSTRACT

The objective of the present study was to investigate into the morphological features of the papillary relief on the toes depending on the age and sex of the adult people and the length of their body and to compare the data obtained with dermatoglyphic patterns of the hands. Fingerprints of 120 male and 80 female central European caucasoids varying in age from 18 to 83 years were studied. The fingerprints were obtained using black printing ink. Special attention was given to the recognition of pattern types, ridge count, rudiments of lines, line density, the distances between the delta and the centre of the pattern or the interphalangeal fold, white lines, scar prints, and other characteristics. The results of the study were treated by the methods of descriptive statistics and correlation analysis. It was shown that coefficients of correlation between the most informative characters and the general personality traits are equal to 0.3-0.4. The regular features of group polymorphism of dermatoglyphic patterns on the toes and fingers were found to be on the whole similar. The correlation coefficients between dermatoglyphic signs on the bilateral and homolateral halves of the body were 0.6-0.8 and 0.2-0.4 respectively. It is concluded that the results of this study provide a basis for the development of the methods for the detection of the general personality traits and the establishment of belonging of the cut-off feet and hands to one or several corpses.


Subject(s)
Dermatoglyphics/classification , Fingers/pathology , Forensic Pathology/methods , Toes/pathology , Adult , Age Factors , Aged , Analysis of Variance , Body Height , Corpse Dismemberment , Female , Humans , Male , Middle Aged , Sex Factors
16.
Forensic Sci Int ; 361: 112142, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38981415

ABSTRACT

Dismemberment and subsequent burning are common methods employed in an attempt to conceal or destroy evidence. While kerf characteristics can be utilised to identify tool(s) used for dismemberment, further research is necessary to assess the effect of burning on these characteristics. In this study, a back (tenon) saw (13 teeth per inch) was used to manually inflict trauma on Ovis aries de-fleshed femur bones (n = 18). Three different cut marks (shallow false start, incomplete cut and complete transection) were made on the mid-shaft of each bone. Subsequently, the bones were burned for 20 minutes in a muffle furnace. Three burn temperatures were assessed: 400 °C, 600 °C and 800 °C. Saw mark characteristics of each cut type were assessed and compared pre- and post-burning. All pre-existing trauma was recognisable post-burning; however, metric and morphological alterations were apparent. An increase in kerf width was observed at 600 °C in false start lesions and 800 °C in incomplete cuts. Breakaway spur thickness decreased post-burning (at 400 °C and 800 °C) but length was not significantly affected. Mean inter-striation distance decreased post burning at all temperature groups. Saw marks were distinguishable from heat-related fractures across all temperature groups. One false start lesion was obliterated at 800 °C. Exit chipping, pull-out striae as well as striation regularity appeared to be more enhanced after heat exposure. These alterations indicate a temperature-dependent impact on these characteristics. Further research is necessary to assess the role of burn duration.


Subject(s)
Hot Temperature , Hot Temperature/adverse effects , Femur/injuries , Femur/pathology , Animals , Corpse Dismemberment , Fires , Humans , Burns/pathology
17.
Sud Med Ekspert ; 56(1): 21-3, 2013.
Article in Russian | MEDLINE | ID: mdl-23789407

ABSTRACT

The main aspects of investigations devoted to forensic medical characteristic of sawed injuries inflicted to the long tubular bones by a power jigsaw are considered. The mathematical model has been developed making it possible to determine the frequency of backward and forward movements of the jigsaw blade from the morphological features of the injuries to long tubular bones of man and to estimate the sawing rate for the further identification of the instrument of crime.


Subject(s)
Corpse Dismemberment , Femur , Weapons/classification , Wounds and Injuries , Adult , Biomechanical Phenomena , Female , Femur/injuries , Femur/pathology , Forensic Pathology/methods , Humans , Male , Middle Aged , Models, Theoretical , Wounds and Injuries/etiology , Wounds and Injuries/pathology
18.
Forensic Sci Int ; 353: 111857, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37871432

ABSTRACT

Forensic toolmark examiners compare marks between those observed on an item/surface and those made by a reference implement, such as a particular tool or weapon, to provide an opinion of the likelihood of common origin. It is widely accepted that such comparison opinions need to be underpinned by empirical research, and this study aimed to add to the knowledge base relied upon when developing and comparing saw marks in bone, a substrate encountered in body dismemberment cases. Porcine bones were used as a human proxy; they were either fresh with residual soft tissue and bodily fluids present ('wet') to replicate dismembered bones shortly post-mortem, or processed to remove soft tissue and moisture content ('dry') to represent cases of dismemberment after an extended period of decomposition and exposure. The bones were cut using one implement of each of five classes: hand saw, mitre saw, reciprocating saw, oscillating saw, and serrated knife. They were cut, either completely through (except for serrated knife), giving two surfaces per cut to examine, or to a depth up to 3 mm (false starts). Five replicates per combination of bone condition, saw, and cut type gave 130 bone samples. These were then cleaned and cast using Isomark Silicone Polymer Compound or Mikrosil, giving 260 cast samples. All bone and cast samples were photographed, examined for various class characteristic markers, and specific markers measured. No significant differences between Isomark and Mikrosil casts were observed when compared side-by-side, demonstrating suitability of both materials for casting of saw marks on bone. Although saw marks presented more class characteristic markers on dry than wet bones, calculations of tooth distances and measurements of kerf width (KW) from marks did not significantly differ between bone conditions, with exception of the reciprocating saw that produced false start marks with significantly larger minimum KW on wet than dry samples. Further analysis supported that tooth distances on marks made by hand and oscillating saws are sufficiently accurate for the determination of saw teeth per inch (TPI). However, one tooth distance on marks made by reciprocating saws did not accurately represent TPI. Finally, examination of presence or absence of class characteristic markers on each saw mark demonstrated consistent variation between saw classes. These results enabled the development of exclusion-based decision trees, and a reference database (available on request), for use by toolmark examiners in their evaluation of saw types based on class characteristic markers observed in cut bone.


Subject(s)
Corpse Dismemberment , Animals , Swine , Humans , Forensic Pathology , Bone and Bones , Empirical Research , Decision Making
19.
J Forensic Sci ; 68(1): 35-45, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36380505

ABSTRACT

Saws are common tools used in postmortem dismemberment to alter human remains. Dismemberment may coincide with other concealment methods such as disposal in aquatic environments, so forensic anthropologists must recognize how taphonomy affects saw mark preservation. This study focuses on exposure of saw cut bone to a fluvial environment. Cross sections from pig humeri cut by a 7 TPI saw were evaluated on all cut surfaces for tooth hop (TH), exit chipping, and breakaway spurs. Pre-fluvial exposure, features were measured by two observers using a stereomicroscope while a one-dimensional profilometer was used to define surface roughness. Bones were randomly assigned to control or experimental groups and within each divided by duration of exposure (24, 48, 72, and 96 h). Control groups (four cross sections) were exposed to water in a 3-meter-long hydraulic channel; experimental groups (20 cross sections) were exposed to water and sediment in a 12-meter-long sediment-recirculating hydraulic channel. Velocity was maintained at 0.45 m/s. All measurements were repeated post-exposure. Observer A recorded 268 TH (mean: 3.70 ± 0.34 mm); post-exposure, count increased by 16.79% (mean: 3.71 ± 0.29 mm). Observer B recorded 247 TH (mean: 3.46 ± 0.42 mm); post-exposure, count decreased by 29.15% (mean: 3.36 ± 0.33 mm). All TPI estimates calculated include the 7 TPI saw. Exit chipping lost flakiness (in both channels), but was still visible. Breakaway spurs were not visibly altered. Surface staining was limited to bones exposed to sediment. Roughness was significantly lower in experimental groups post-fluvial exposure (W = 5705, p < 0.05). Overall, this fluvial environment did not obliterate saw mark evidence from bone.


Subject(s)
Corpse Dismemberment , Animals , Autopsy , Humerus , Microscopy , Swine , Water
20.
J Forensic Sci ; 68(1): 257-266, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36411482

ABSTRACT

Minimum kerf width (MKW) is often assessed in medicolegal cases of skeletal sharp force trauma and can provide information about the tool used. Previously published saw MKW research focuses on the relationship between MKW and saw blade set width (width of the saw blade including tooth set). Despite these publications using various measurement tools and methods to collect MKW, error in MKW measurements is not well-documented. The goal of this research was to investigate MKW measurement precision in terms of intraobserver error, interobserver error, and the effects of measurement modality (e.g., calipers versus stereo microscope). The study sample consisted of 351 incomplete cuts made with 27 diverse saws. MKW was collected using three methods: (1) inserting the internal caliper jaws into the incomplete kerf, (2) placing the external caliper jaws on the cortical surface, and (3) using a digital stereo microscope and associated measurement software. For each method, intraobserver error and interobserver error were assessed. Differences in measurements taken with the three measurement modalities were assessed for each observer as well. Relative technical error of measurement (rTEM) and coefficients of reliability indicate that internal caliper and stereo microscope measurements had the lowest intra- and interobserver error (rTEM = 3.72% to 6.15%; r = 0.98-0.996). External caliper measurements performed the worst (rTEM: intra = 8.53% and inter = 21.32%). There was higher precision between internal caliper and stereo microscope measurements than with the external caliper measurements. This research highlights the need for measurement standardization.


Subject(s)
Corpse Dismemberment , Microscopy , Humans , Reproducibility of Results , Observer Variation
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