Citrate Content of Bone for Time Since Death Estimation: Results from Burials with Different Physical Characteristics and Known PMI

A recently introduced method to determine the postmortem interval (PMI) based on quantification of the citrate content in bone was applied on the temporal bones and femora of 20 individuals buried in wooden coffins (WO) and body bags (BB), respectively. Concerning known vs. calculated PMI, a significant difference between the temporal and the femur bone samples of the same individuals was observed in the BB group (p = 0.012). In contrast, differences were insignificant for the WO group (p = 0.400). Moreover, similar levels of underestimation of PMIs resulted from the analysis of the femora for both burial groups (p = 0.247). Also, there was consistently less citrate preserved in the flat temporal bones as compared to the femora, indicating that the cortical layer of the long bones should be preferentially employed for citrate‐based PMI estimations. The results call for additional research on subsurface‐buried and surface‐deposited remains to enhance the accuracy of the published PMI equation.     

Estimating the Temperature of Heat‐exposed Bone via Machine Learning Analysis of SCI Color Values: A Pilot Study

Determining maximum heating temperatures of burnt bones is a long‐standing problem in forensic science and archaeology. In this pilot study, controlled experiments were used to heat 14 fleshed and defleshed pig vertebrae (wet bones) and archaeological human vertebrae (dry bones) to temperatures of 400, 600, 800, and 1000°C. Specular component included (SCI) color values were recorded from the bone surfaces with a Konica‐Minolta cm‐2600d spectrophotometer. These color values were regressed onto heating temperature, using both a traditional linear model and the k‐nearest neighbor (k‐NN) machine‐learning algorithm. Mean absolute errors (MAE) were computed for 1000 rounds of temperature prediction. With the k‐NN approach, the median MAE prediction errors were 41.6°C for the entire sample, and 20.9°C for the subsample of wet bones. These results indicate that spectrophotometric color measurements combined with machine learning methods can be a viable tool for estimating bone heating temperature.     

A Simple and Efficient Method of Extracting DNA from Aged Bones and Teeth

DNA is often difficult to extract from old bones and teeth due to low levels of DNA and high levels of degradation. This study established a simple yet efficient method for extracting DNA from 20 aged bones and teeth (approximately 60 years old). Based on the concentration and STR typing results, the new method of DNA extraction (OM) developed in this study was compared with the PrepFiler? BTA Forensic DNA Extraction Kit (BM). The total amount of DNA extracted using the OM method was not significantly different from that extracted using the commercial kit (p > 0.05). However, the number of STR loci detected was significantly higher in the samples processed using the OM method than using the BM method (p < 0.05). This study aimed to establish a DNA extraction method for aged bones and teeth to improve the detection rate of STR typing and reduce costs compared to the BM technique.     

A Reliable Regression‐Based Approach for Reassociating Human Skeletal Elements of the Lower Limbs from Commingled Assemblages

Accurate sorting of commingled human remains comprises a fundamental requirement for all further anthropological analyses. The lower limb bones are particularly important for reconstructing biological profiles. This study introduces a metric technique for sorting these elements using eight standard anthropological measurements and 222 adult individuals from Greece. The bones utilized were the os coxae, the femora, the tibiae and the tali. Simple regression analyses were used to develop functions for reassociating articulating bones, providing strong correlations (r = 0.74–0.95, p‐value <0.05) and high coefficients of determination (r²=0.54–0.91). Blind tests demonstrated that combining metric and morphoscopic techniques provides an excellent sorting accuracy for the hip and knee joints (ten of ten individuals), allowing for a reliable reassociation between a sex and age indicator (os coxae) and a body size indicator (femur). Overall, these results indicate the high value of metric methods in sorting commingled human remains.     

Applying Knowledge of Species‐Typical Scavenging Behavior to the Search and Recovery of Mammalian Skeletal Remains

Forensic investigations involving animal scavenging of human remains require a physical search of the scene and surrounding areas. However, there is currently no standard procedure in the U.K. for physical searches of scavenged human remains. The Winthrop and grid search methods used by police specialist searchers for scavenged remains were examined through the use of mock red fox (Vulpes vulpes) scatter scenes. Forty‐two police specialist searchers from two different regions within the U.K. were divided between those briefed and not briefed with fox‐typical scavenging information. Briefing searchers with scavenging information significantly affected the recovery of scattered bones (χ² = 11.45, df = 1, p = 0.001). Searchers briefed with scavenging information were 2.05 times more likely to recover bones. Adaptions to search methods used by searchers were evident on a regional level, such that searchers more accustom to a peri‐urban to rural region recovered a higher percentage of scattered bones (58.33%, n = 84).     

Shells and Bones: A Forensic Medicine Study of the Association of Terrestrial Snail Allopeas micra with Buried Human Remains in Brazil

Little is known regarding the scavenger fauna associated with buried human corpses, particularly in clandestine burials. We report the presence of 20 shells of the terrestrial snail Allopeas micra, within hollow bones of human remains buried for 5 years, during the process of collecting DNA material. The fact that a large number of shells of A. micra had been found in the corpse and in the crime scene supports the assumption that there was no attempt to remove the corpse from the area where the crime occurred. Despite this, our observations cannot be used to estimate the postmortem interval because there is no precise knowledge about the development of this species. This is the first record of a terrestrial snail associated with a human corpse and its role in this forensic medicine case.     

Sex Determination from the Second Cervical Vertebra: A Test of Wescott’s Method on a Modern American Sample*

Abstract: Numerous methods for establishing a biological profile exist; however, many of these methods rely on the recovery of several specific bones or on fragile skeletal elements that are sometimes irrecoverable. It is for this reason new methods utilizing other previously under‐documented bones should be established and tested by the forensic anthropological community. This study tests the accuracy of Wescott’s (J Forensic Sci 2000;45(2)) method for determining sex from the second cervical vertebra. Specimens were drawn from the donated skeletal collection curated at the Hamilton County Forensic Center (n = 57) and the William M. Bass Donated Skeletal Collection (n = 243). Both intra‐ and inter‐observer error rates were low and accurate classifications ranged from 78% (females‐Function 1) to 90.6% (males‐Function 5). Of the five functions, Function 4 achieved the highest overall accuracy, with 260 individuals (86.7%) falling into the correct category. Overall, this method is an effective classificatory tool for sex estimation.     

Recognition of Skeletal Fractures in Infants: An Autopsy Technique

Abstract:  Complete recognition and documentation of injury pattern is crucial in the diagnosis of child abuse. Skeletal fractures regarded as highly specific to nonaccidental injury in infants include posterior rib, scapular, metaphyseal, and spinous process fractures. These injuries are often occult, especially when acute, to standard radiologic and autopsy procedures. The presented autopsy technique requires incising and reflecting skeletal muscles to expose the bones and costal osseous joints in situ , increasing the opportunity to recognize skeletal injury. Fractured or atypical appearing bones are removed and processed for complete evaluation. The bones are processed by macerating the soft tissue in a water soap bath at an elevated temperature. To aid in reconstruction of the decedent, long bones are replaced with wooden dowels and the chest cavity is packed with the organ bag. The technique is invasive and recommended for cases in which the pathologist has reasonable suspicion of acute or remote trauma.     

A Comparative Assessment of the Chen et al. and Suchey‐Brooks Pubic Aging Methods on a North American Sample, ,

Accurately estimating the age‐at‐death of adult human skeletons is fundamental in forensic anthropology. This study evaluates the accuracy of two pubic bone age estimation methods—Chen et al. and Suchey‐Brooks. Specimens were obtained from a known collection of modern pubic bones curated at the Maricopa County Forensic Science Center in Phoenix, Arizona. A sample of 296 left male pubic bones of European ancestry was statistically evaluated via bias, absolute mean error, and intra‐ and inter‐observer error. Results indicate that the two methods are similar; the Suchey‐Brooks method is the most accurate for aging young adults (error c. 7 years), while the Revised Chen et al. method is most accurate for aging middle‐age adults (error c. 6 years). Thus, the Chen et al. method is an important contribution to forensic anthropology for aging older adult skeletal remains. There are, however, some limitations such as subjectivity and the intricate scoring system of Chen et al. method.     

Taphonomic Effects of Vulture Scavenging*

Abstract: From July through September 2007, three pig carcasses (Sus scrofa), weighing between 27 and 63 kg were placed outside in a grassy area in central Texas. A surrounding fence prevented entrance by terrestrial scavengers, while allowing avian scavengers unrestricted access. A fourth pig carcass served as a control for the rate of decomposition and was placed in a cage that prevented terrestrial and avian animal access. Modification of the carcasses was recorded through the use of two motion‐sensing digital cameras and daily on‐site observations. American black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) waited c. 24 h before beginning to scavenge and completely skeletonized the carcasses in 3 to 27 h of feeding, leaving scratches on the bones. The accelerated rate of decomposition and the signature markings on the bones should be considered when interpreting taphonomic events and determining an accurate postmortem interval at vulture‐modified scenes.     

Reanalysis of the Trotter Tibia Quandary and its Continued Effect on Stature Estimation of Past‐Conflict Service Members

Forensic casework from past‐conflicts relies on the corrected historical Trotter data for stature estimation in Fordisc. For roughly 10 years’, stature estimation using this data has produced point estimates for the tibia that are on average 1.25 inches less than the other long bones. This issue was identified after applying the equations derived from Fordisc to the USS Oklahoma commingled assemblage. Reevaluation of Fordisc revealed that a correction factor of 20 mm, instead of 10 mm, was mistakenly applied to the Trotter tibia data. Historical forensic anthropology reports written at the Defense POW/MIA Accounting Agency were utilized to identify that the overcorrection is isolated to Fordisc 3 with an error rate of 5% of known antemortem statures falling outside of the prediction intervals that relied on the tibia. Further evaluation of the Oklahoma sample indicates the 10 mm correction is still producing point estimates less than the other long bones.     

Effects of kinetic energy and firearm-to-target distance on fracture behavior in flat bones

This research implements a fractographic approach to investigate the relationships between kinetic energy, firearm-to-target distance, and various aspects of fracture behavior in gunshot trauma. Gunshot experiments were performed on pig scapulae (n = 30) using three firearms generating different muzzle (initial) kinetic energies, including a 0.32 pistol (103 J), 0.40 pistol (492 J), and 0.308 rifle (2275 J). Specimens were shot from two distances: 10 cm (n = 15) and 110 cm (n = 15). Features evaluated in fractographic analysis such as cone cracks, radiating cracks, crack branching points, and circumferential cracks could be easily identified and measured in flat bones and allowed for statistical comparison of crack propagation behavior under different impact conditions. Higher-energy bullets produced more radiating cracks, more crack branching points, and longer fracture lengths than lower-energy bullets. Distance had no significant effect on fracture morphology at the distances tested. That quantitative measures of crack propagation varied with energy affirms that kinetic energy transfer is important in determining the nature and extent of fracture in gunshot wounds and suggests it may be possible to infer relatively high- versus relatively low-energy transfer using these features. Ranges obtained with the three firearms exhibited considerable overlap, however, indicating that other variables such as bullet caliber, mass, and construction influence the efficiency of energy transfer from bullet to bone. Therefore, fracture morphology cannot be used to identify a specific firearm or to directly reconstruct the muzzle (initial) kinetic energy in forensic cases.     

The application of ultraviolet irradiation to exogenous sources of DNA in plasticware and water for the amplification of low copy number DNA

Using high sensitivity forensic STR polymerase chain reaction (PCR) typing procedures, we have found low concentrations of DNA contamination in plasticware and water assumed to be sterile, which is not detected by standard DNA procedures. One technique commonly used to eliminate the presence of DNA is ultraviolet (UV) irradiation; we optimized such a protocol used in the treatment of water, tubes, plates, and tips for low copy number DNA (LCN) amplification. UV light from a Stratalinker((R)) 2400 was administered to 0.2, 1.5 mL tubes, and PCR plates contaminated with up to 500 pg of DNA. They were subsequently quantified with an ALU-based real-time PCR method using the Rotorgene 3000. Overall, there was a decrease in concentration of DNA recovered as the duration of treatment increased. Nonetheless, following 45 min of irradiating a PCR plate with 500 pg of DNA, nearly 6 pg were still detected. However, when the plate was raised within an inch of the UV source, less than 0.2 pg of DNA was detected. Additionally, lining the area around the samples with aluminum foil further reduced the amount of time necessary for irradiation, as only 30 min eliminated the presence DNA in the raised PCR plate. Similar experiments were conducted using tubes filled with a solution of DNA and water in equivalent concentrations for 50, 15, and 1.5 mL tubes with comparative results. It is plausible that the aluminum foil increased the amount of reflection in the area thereby enhancing penetration of UV rays through the walls of the plasticware. This protocol was tested for the possibility of inhibitors produced from irradiation of plastic tubes. As our protocols require less irradiation time than previous studies, PCR sensitivity was not affected. Moreover, the lifespan of the UV lamps was extended. Our findings demonstrate that this method is useful as an additional precautionary measure to prevent amplification of extraneous DNA from plasticware and water without compromising the sensitivity of LCN DNA amplifications.     

An Examination of the Transition of Fracture Characteristics in Long Bones from Fresh to Dry in Central Florida: Evaluating the Timing of Injury

It is important to conduct timing of injury research analyzing fracture characteristics at known postmortem intervals (PMI) because bone can retain fresh characteristics throughout the PMI. Defleshed pig (Sus scrofa) long bones were fractured weekly in two environments (full sun and shade) over 14 weeks in Central Florida and fracture characteristics were categorized (N = 136) for analysis. Results of analysis of variance (ANOVA) using time in weeks (PMI) as a dependent variable indicate significant relationships between PMI and Fracture Angle (p < 0.001), Fracture Surface (p < 0.001), and Fracture Outline (p < 0.001). Fracture characteristics associated with perimortem trauma (smooth Fracture Surfaces and curved or V‐shaped Fracture Outlines) were commonly observed. Analysis of fracture characteristics for each environment demonstrated similar patterns. Overall, the loss of only fresh fracture characteristics for each bone was noted earlier in the PMI for the Central Florida region than previously reported.     

儿童骨骼特征的组织学研究

目的研究儿童骨骼的组织学特征,为儿童骨骼残片的法医学鉴定提供科学依据。方法提取儿童四肢长骨骨片,制作骨骼的组织切片,在显微镜下观察内、外环骨板,骨单位,骨细胞的组织学结构,比较儿童骨骼与动物及成人骨骼的组织学区别。结果儿童骨骼的骨单位形态与成人相似,骨单位间存在大量的内层骨板,与动物的骨组织特征相似。结论根据骨组织学特征,可以确定儿童的骨骼残片。     

Forensic Approach to an Archaeological Casework of “Vampire” Skeletal Remains in Venice: Odontological and Anthropological Prospectus*

Abstract: During the years 2006–2007, the Archeological Superintendent of Veneto (Italy) promoted a research project on mass graves located on Nuovo Lazzaretto in Venice, where the corpses of plague deaths were buried during the 16th and 17th centuries. The burials were of different stages and are believed to be the remains of plague victims from the numerous outbreaks of pestilence, which occurred between the 15th and 17th centuries. Among the fragmented and commingled human bones, an unusual burial was found. The body was laid supine, with the top half of the thorax intact, arms parallel to the rachis axis, the articulations were anatomically unaltered. Both the skull morphology and the dimensions of the caput omeris suggest the body was a woman. A brick of moderate size was found inside the oral cavity, keeping the mandible wide open. The data collected by the anthropologist were used to generate a taphonomic profile, which precluded the positioning of the brick being accidental. Likewise, the probability of the brick having come from the surrounding burial sediment was rejected, as the only other inclusions found were bone fragments from previous burials in the same area. The data collected by the odontologist were employed for age estimation and radiological dental assessment. The forensic profile was based conceptually on the “circumstances of death” and concluded that the positioning of the brick was intentional, and attributed to a symbolic burial ritual. This ritual confirms the intimate belief held at those times, between the plague and the mythological character of the vampire.     

Identification of Different Forms of Cocaine and Substances Used in Adulteration Using Near‐infrared Raman Spectroscopy and Infrared Absorption Spectroscopy

Identification of cocaine and subsequent quantification immediately after seizure are problems for the police in developing countries such as Brazil. This work proposes a comparison between the Raman and FT‐IR techniques as methods to identify cocaine, the adulterants used to increase volume, and possible degradation products in samples seized by the police. Near‐infrared Raman spectra (785 nm excitation, 10 sec exposure time) and FT‐IR‐ATR spectra were obtained from different samples of street cocaine and some substances commonly used as adulterants. Freebase powder, hydrochloride powder, and crack rock can be distinguished by both Raman and FT‐IR spectroscopies, revealing differences in their chemical structure. Most of the samples showed characteristic peaks of degradation products such as benzoylecgonine and benzoic acid, and some presented evidence of adulteration with aluminum sulfate and sodium carbonate. Raman spectroscopy is better than FT‐IR for identifying benzoic acid and inorganic adulterants in cocaine.     

Effect of Temperature on the Visualization by Digital Color Mapping of Latent Fingerprint Deposits on Metal

Visualization of fingerprint deposits by digital color mapping of light reflected from the surface of heated brass, copper, aluminum, and tin has been investigated using Adobe^® Photoshop^®. Metals were heated to a range of temperatures (T) between 50°C and 500°C in 50°C intervals with enhancement being optimal when the metals are heated to 250°C, 350°C, 50°C, and 300°C, respectively, and the hue values adjusted to 247°, 245°, 5°, and 34°, respectively. Fingerprint visualization after color mapping was not degraded by subsequent washing of the metals and color mapping did not compromise the visibility of the fingerprint for all values of T. The optimum value of T for fingerprint visibility is significantly dependent of the standard reduction potential of the metal with Kendall's Tau (τ) = 0.953 (p < 0.001). For brass, this correlation is obtained when considering the standard reduction potential of zinc rather than copper.     

Pontomedullary lacerations in falls from a height--a retrospective autopsy study

Brainstem pontomedullary laceration (PML) in falls from a height appears as isolated cases and usually in feet-first impacts with a ring fracture. The aim of this study was to determine the frequency of PML in falls from a height, as well as the frequency of concomitant head and neck injuries. Out of 261 cases, PML was present in 40. An impact to the chin, as well as a feet- or buttocks-first impact, most often led to PML owing to transmission of the impact force. Also, a lateral, frontal, or posterior head impact, with subsequent hinge fracture, as well as the frontoposterior hyperextension of the head associated with an upper spine fracture, could be possible mechanisms of PML in falls from a height. The jawbone and other facial bones act as shock absorbers, and their fracture diminishes energy transfer toward the skull and protects the brain and brainstem from injury.