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1.
Am J Phys Anthropol ; 168(2): 279-291, 2019 02.
Article in English | MEDLINE | ID: mdl-30593657

ABSTRACT

OBJECTIVES: The Baltic region, particularly Lithuania, was a politically vibrant area of Eastern Europe during the medieval and early modern period. To better understand the diet of Lithuanians during the late 14th to early 18th century, we examine stable carbon and nitrogen isotope ratios from bone and dentin samples from the site of Alytus. We investigate possible dietary differences based on sex, age, and religious practice, as well as dietary changes throughout an individual's lifetime, within the broader European milieu. MATERIALS AND METHODS: Stable carbon and nitrogen isotope analysis was conducted on bone (n = 35) and dentin (n = 38) collagen samples from a total of 39 individuals buried in the cemetery at Alytus (late 14th to early 18th centuries). RESULTS: Results indicate individuals at Alytus consumed a C3 terrestrial based diet. The ƎĀ“13 C and ƎĀ“15 N values are not significantly different between bone and dentin, and did not vary by sex. DISCUSSION: The diet at Alytus was homogeneous between males and females and between tissue types. The lack of evidence indicating substantial consumption of fish is unexpected given widespread Catholic fasting practices and marine resource trade throughout Europe. Comparisons with other populations indicate that individuals from Alytus differ in diet from contemporaneous Polish-Lithuanian Commonwealth elites. Comparison of the diets of non-elite individuals in the Eastern Baltic region also reveals dietary variability.


Subject(s)
Carbon Isotopes/analysis , Diet/history , Nitrogen Isotopes/analysis , Adult , Animals , Anthropology, Physical , Bone and Bones/chemistry , Collagen/chemistry , Dentin/chemistry , Female , History, 15th Century , History, 16th Century , History, 17th Century , History, 18th Century , History, Medieval , Humans , Lithuania , Male , Middle Aged , Young Adult
2.
Sci Justice ; 55(2): 131-8, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25753999

ABSTRACT

Forensic anthropologists are generally able to identify skeletal materials (bone and tooth) using gross anatomical features; however, highly fragmented or taphonomically altered materials may be problematic to identify. Several chemical analysis techniques have been shown to be reliable laboratory methods that can be used to determine if questionable fragments are osseous, dental, or non-skeletal in nature. The purpose of this review is to provide a detailed background of chemical analysis techniques focusing on elemental compositions that have been assessed for use in differentiating osseous, dental, and non-skeletal materials. More recently, chemical analysis studies have also focused on using the elemental composition of osseous/dental materials to evaluate species and provide individual discrimination, but have generally been successful only in small, closed groups, limiting their use forensically. Despite significant advances incorporating a variety of instruments, including handheld devices, further research is necessary to address issues in standardization, error rates, and sample size/diversity.


Subject(s)
Bone and Bones/chemistry , Dental Enamel/chemistry , Trace Elements/analysis , Animals , Cremation , Forensic Anthropology , Humans , Microscopy , Species Specificity , Spectrometry, X-Ray Emission , Spectroscopy, Near-Infrared , Spectrum Analysis, Raman
3.
Forensic Sci Int ; 363: 112197, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39151242

ABSTRACT

Evaluating sharp force trauma (SFT) injuries to bone inflicted by a larger class of chopping/hacking tools (i.e., swords, axes, hatchets, machetes, and cleavers) is a growing area within the field of forensics. Previous studies have demonstrated promise regarding tool differentiation through the utilization of microscopic cut mark characteristics. However, this is an area that warrants additional investigation as there has yet to be a comprehensive study that incorporates the majority of these microscopic chopping/hacking cut mark characteristics into one analysis. The purpose of the current research was to analyze a large sample of microscopic cut mark characteristics derived from the current chopping/hacking literature to determine if differentiation of tool type could be made based on the microscopic cut mark characteristics. An additional goal of the current research is to develop standardization guidelines for the assessment of cut marks, focusing on a comprehensive suite of microscopic cut mark characteristics commonly observed in the existing literature. The skeletal sample for the current research was derived from a previous macroscopic cut mark characteristic experiment where trauma was inflicted to 20 partially fleshed domestic pig (Sus scrofa domesticus) limbs utilizing four chopping/hacking tools (i.e., axe, hatchet, machete, and cleaver) as well as a large carving knife for comparison. Cut marks were evaluated for 15 microscopic cut mark characteristics to assess statistical significance. Utilizing a chi-square analysis, nine of the 15 microscopic cut mark characteristics demonstrated statistically significant differences in relation to the tool utilized, indicating moderate to relatively strong effect sizes. For example, it should be possible to use a combination of microscopic cut mark characteristics to potentially indicate which chopping/hacking tool inflicted trauma when analyzing bones. In particular, examining the characteristics such as regularity of the cut mark edges along with the occurrence of uprising, fossae/depressions, and microscopic fractures can suggest or exclude tool class within forensic contexts.


Subject(s)
Microscopy , Animals , Swine , Wounds, Stab/pathology , Models, Animal , Forensic Pathology/methods , Weapons , Forensic Anthropology
4.
J Forensic Sci ; 69(4): 1138-1154, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38600623

ABSTRACT

In forensic anthropology, osteological sex estimation methods are continuously reevaluated and updated to improve classification accuracies. Therefore, to gain a comprehensive understanding of recent trends in sex estimation research in forensic anthropology, a content analysis of articles published between 2000 and 2022 in Forensic Science International, the Journal of Forensic Sciences, the International Journal of Legal Medicine, the American Journal of Biological Anthropology, and Forensic Anthropology, was performed. The main goals of this content analysis were to (1) examine trends in metric versus morphological research, (2) examine which areas of the skeleton have been explored, (3) examine which skeletal collections and population affinities have been most frequently utilized, and (4) determine which statistical methods were commonly implemented. A total of 440 articles were coded utilizing MAXQDA and the resulting codes were exported for analysis. Statistical analyses were conducted utilizing the Cochran-Armitage and Jonckheere-Terpstra tests for trends, as well as Fisher-Freeman-Halton tests. The results demonstrate that sex estimation research published in these journals has prioritized metric over morphological methods. Further, the most utilized skeletal regions continue to be the skull and pelvis, while the most popular classification statistics continue to be discriminant function analysis and logistic regression. This study also demonstrates that a substantial portion of research has been conducted utilizing U.S. and Europe-based collections and limited populations. Based on these results, future sex estimation research must continue exploring the use of long bones and other postcranial elements, testing newer methods of analysis, as well as developing population-inclusive methods.


Subject(s)
Forensic Anthropology , Periodicals as Topic , Sex Determination by Skeleton , Humans , Sex Determination by Skeleton/methods , Forensic Anthropology/trends , Periodicals as Topic/trends , Bibliometrics , Research/trends , Male , Discriminant Analysis
5.
J Forensic Sci ; 53(2): 279-87, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18366561

ABSTRACT

Ground-penetrating radar (GPR) was used to monitor 12 pig burials in Florida, each of which contained a small pig cadaver. Six of the cadavers were buried in sand at a depth of 0.50-0.60 m, and the other six were buried in sand at a depth of 1.00-1.10 m to represent deep and shallow burials that are generally encountered in forensic scenarios. Four control excavations with no pig interment were also constructed as blank graves and monitored with GPR. The burials were monitored for durations of either 13 or 21 months, and were then excavated to correlate the decomposition state of the cadaver with the GPR imagery. Overall, this study demonstrated that it may be difficult to detect small cadavers buried in sand soon after they are skeletonized because the area surrounding the body, or the grave, may not provide a strong enough contrasting area to be detected by GPR when compared to that of the surrounding undisturbed soil. Also, depth of burial appears to influence grave detection because bodies that are buried at deeper depths may be detected for a longer period of time due to reduced decomposition rates.


Subject(s)
Burial , Radar , Animals , Cadaver , Electromagnetic Fields , Forensic Anthropology/methods , Swine
6.
J Forensic Sci ; 63(4): 1021-1032, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29211936

ABSTRACT

Scavengers can significantly alter a forensic scene and consume, modify, disarticulate, and disperse bodies on the ground surface. The research purpose was to examine vulture scavenging in central Florida, USA. Four small-sized pig (Sus scrofa) carcasses were left on the ground surface of two microenvironments (shaded and open) at a secure site with game cameras. Dispersal data were mapped and analyzed using geographical information systems spatial analysis digital mapping tools. The primary avian scavengers recorded included black vultures (Coragyps atratus) and turkey vultures (Cathartes aura), as well as bald eagles (Haliaeetus leucocephalus). Carcass dispersal patterns were impacted by foliage density (grass height and concentrations of bushes and trees) and proximity to the perimeter fence. While the majority of skeletal elements were dispersed within 6 m of the carcass deposition locations, dispersion occurred over a greater distance in the wooded microenvironment. Overall, vulture behaviors deleteriously destroyed and changed the context of the scene, with black vultures having the greatest impact.


Subject(s)
Birds , Feeding Behavior , Geographic Information Systems , Postmortem Changes , Animals , Models, Animal , Opossums , Spatial Analysis , Swine
7.
Forensic Sci Int ; 290: 85-93, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30015283

ABSTRACT

Regardless of region, skeletal remains deposited in subaerial contexts are subjected to a progression of taphonomic alterations. However, there are limited postmortem interval (PMI) standards developed, particularly in environments where skeletonization can occur quickly. The research purpose was to evaluate the timing and progression of early weathering alterations in two microenvironments (shaded and open) using pig carcasses (Sus scrofa) in the subtropical humid environment of central Florida. Over nine months, sun bleaching was assessed using MunsellĀ® Soil Color Charts (2009) and scored based on percentage of the bone sun bleached, while bone weathering was further evaluated using Behrensmeyer's (1978) stages. Results indicate that microenvironment has a significant influence, with the onset and progression of sun bleaching and Behrensmeyer's (1978) Stages 2 and 3 occurring earlier in the open microenvironment. Sun bleaching stages and Behrensmeyer's (1978) weathering stages can be utilized in conjunction for developing regionally specific PMI taphonomic models for different microenvironments.


Subject(s)
Bone and Bones/pathology , Humidity , Postmortem Changes , Sunlight , Animals , Florida , Forensic Anthropology , Models, Animal , Swine
8.
J Forensic Sci ; 62(2): 282-291, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27864956

ABSTRACT

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.


Subject(s)
Femoral Fractures/pathology , Humeral Fractures/pathology , Postmortem Changes , Tibial Fractures/pathology , Animals , Desiccation , Florida , Forensic Anthropology , Models, Animal , Sunlight , Swine , Weather
9.
J Forensic Sci ; 51(3): 607-16, 2006 May.
Article in English | MEDLINE | ID: mdl-16696709

ABSTRACT

Ground-penetrating radar (GPR) was used to monitor 12 pig burials in Florida, each of which contained a large pig cadaver. Six of the cadavers were buried in sand at a depth of 0.50-0.60 m, and the other six were buried at a depth of 1.00-1.10 m and were in contact with the upper surface of a clay horizon. Control excavations with no pig internment were also constructed as blank graves and monitored with GPR. The burials were monitored with GPR for durations of either 12-13 or 21-21.5 months when they were then excavated to correlate the decomposition state of the cadaver with the GPR imagery. Overall, cadavers in sand were easily detected for the duration of this study at 21.5 months, even when completely skeletonized. Conversely, in clay it became increasingly difficult to image the pig cadavers over the first year of burial, even when they still retained extensive soft tissue structures.


Subject(s)
Burial , Forensic Anthropology/methods , Postmortem Changes , Radar , Animals , Soil , Swine
10.
J Forensic Sci ; 60(2): 382-90, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25620077

ABSTRACT

One of the tasks of a forensic anthropologist is to sort human bone fragments from other materials, which can be difficult when dealing with highly fragmented and taphonomically modified material. The purpose of this research is to develop a method using handheld X-ray fluorescence (HHXRF) spectrometry to distinguish human and nonhuman bone/teeth from nonbone materials of similar chemical composition using multivariate statistical analyses. The sample materials were derived primarily from previous studies: human bone and teeth, nonhuman bone, nonbiological materials, nonbone biological materials, and taphonomically modified materials. The testing included two phases, testing both the reliability of the instrument and the accuracy of the technique. The results indicate that osseous and dental tissue can be distinguished from nonbone material of similar chemical composition with a high degree of accuracy (94%). While it was not possible to discriminate rock apatite and synthetic hydroxyapatite from bone/teeth, this technique successfully discriminated ivory and octocoral.


Subject(s)
Bone and Bones , Spectrometry, X-Ray Emission , Tooth , Animals , Calcium/analysis , Forensic Anthropology/methods , Humans , Phosphorus/analysis , Principal Component Analysis , Species Specificity
11.
J Forensic Sci ; 60(6): 1534-41, 2015 11.
Article in English | MEDLINE | ID: mdl-26234321

ABSTRACT

Identification of osseous materials is generally established on gross anatomical features. However, highly fragmented or taphonomically altered materials may be problematic and may require chemical analysis. This research was designed to assess the use of scanning electron microscopy-energy-dispersive X-ray spectrometry (SEM/EDX), elemental analysis, and multivariate statistical analysis (principal component analysis) for discrimination of osseous and nonosseous materials of similar chemical composition. Sixty samples consisting of osseous (human and nonhuman bone and dental) and non-osseous samples were assessed. After outliers were removed a high overall correct classification of 97.97% was achieved, with 99.86% correct classification for osseous materials. In addition, a blind study was conducted using 20 samples to assess the applicability for using this method to classify unknown materials. All of the blind study samples were correctly classified resulting in 100% correct classification, further demonstrating the efficiency of SEM/EDX and statistical analysis for differentiation of osseous and nonosseous materials.


Subject(s)
Microscopy, Electron, Scanning , Multivariate Analysis , Principal Component Analysis , Spectrometry, X-Ray Emission , Animal Shells/chemistry , Animals , Apatites/chemistry , Bone and Bones/chemistry , Calcium Carbonate/chemistry , Dental Enamel/chemistry , Dentin/chemistry , Forensic Sciences/methods , Glass/chemistry , Humans , Plastics/chemistry , Sea Urchins/chemistry , Starfish/chemistry , Wood/chemistry
12.
J Forensic Sci ; 60(3): 743-52, 2015 May.
Article in English | MEDLINE | ID: mdl-25684166

ABSTRACT

Forensic investigators routinely deploy side-scan sonar for submerged body searches. This study adds to the limited body of literature by undertaking a controlled project to understand how variables affect detection of submerged bodies using side-scan sonar. Research consisted of two phases using small and medium-sized pig (Sus scrofa) carcasses as proxies for human bodies to investigate the effects of terrain, body size, frequency, swath width, and state of decomposition. Results demonstrated that a clear, flat, sandy pond floor terrain was optimal for detection of the target as irregular terrain and/or vegetation are major limitations that can obscure the target. A higher frequency towfish was preferred for small bodies, and a 20 m swath width allowed greater visibility and easier maneuverability of the boat in this environment. Also, the medium-sized carcasses were discernable throughout the 81-day study period, indicating that it is possible to detect bodies undergoing decomposition with side-scan sonar.


Subject(s)
Immersion , Sound , Water , Animals , Diagnosis , Forensic Sciences/methods , Humans , Models, Animal , Ponds , Sus scrofa
13.
J Forensic Sci ; 47(3): 656-9, 2002 May.
Article in English | MEDLINE | ID: mdl-12051357

ABSTRACT

Contemporary commercial cremation is a reductive taphonomic process that represents one of the most extreme examples of postmortem human alteration of bone. The thorough reduction and fragmentation of cremated human remains often leaves little biological evidence of diagnostic value. Instead, non-osseous artifacts often provide the best evidence of the origin of the cremated remains, the identity of the decedent, and commingling of the remains of more than one individual. Once human remains have been cremated they are most commonly placed into a processor and reduced into small fragments and fine ash suitable for inurnment or scattering. The type of processor determines the size and utility of the particulates and artifacts available for analysis. The newest type of processors have changed the manner and degree of postmortem bone modification and altered the preservation of diagnostic bone fragments and cremation artifacts. This paper addresses the impact of the newest cremation procedures on forensic analysis of cremated remains.


Subject(s)
Forensic Anthropology/methods , Mortuary Practice/methods , Humans , Mortuary Practice/instrumentation
14.
Forensic Sci Int ; 228(1-3): e33-46, 2013 May 10.
Article in English | MEDLINE | ID: mdl-23489743

ABSTRACT

Scene mapping is an integral aspect of processing a scene with scattered human remains. By utilizing the appropriate mapping technique, investigators can accurately document the location of human remains and maintain a precise geospatial record of evidence. One option that has not received much attention for mapping forensic evidence is the differential global positioning (DGPS) unit, as this technology now provides decreased positional error suitable for mapping scenes. Because of the lack of knowledge concerning this utility in mapping a scene, controlled research is necessary to determine the practicality of using newer and enhanced DGPS units in mapping scattered human remains. The purpose of this research was to quantify the accuracy of a DGPS unit for mapping skeletal dispersals and to determine the applicability of this utility in mapping a scene with dispersed remains. First, the accuracy of the DGPS unit in open environments was determined using known survey markers in open areas. Secondly, three simulated scenes exhibiting different types of dispersals were constructed and mapped in an open environment using the DGPS. Variables considered during data collection included the extent of the dispersal, data collection time, data collected on different days, and different postprocessing techniques. Data were differentially postprocessed and compared in a geographic information system (GIS) to evaluate the most efficient recordation methods. Results of this study demonstrate that the DGPS is a viable option for mapping dispersed human remains in open areas. The accuracy of collected point data was 11.52 and 9.55 cm for 50- and 100-s collection times, respectfully, and the orientation and maximum length of long bones was maintained. Also, the use of error buffers for point data of bones in maps demonstrated the error of the DGPS unit, while showing that the context of the dispersed skeleton was accurately maintained. Furthermore, the application of a DGPS for accurate scene mapping is discussed and guidelines concerning the implementation of this technology for mapping human scattered skeletal remains in open environments are provided.


Subject(s)
Bone and Bones , Geographic Information Systems , Maps as Topic , Environment , Forensic Anthropology/methods , Humans , Software
15.
Forensic Sci Int ; 231(1-3): 306-16, 2013 Sep 10.
Article in English | MEDLINE | ID: mdl-23890654

ABSTRACT

Forensic personnel must deal with numerous challenges when searching for submerged objects. While traditional water search methods have generally involved using dive teams, remotely operated vehicles (ROVs), and water scent dogs for cases involving submerged objects and bodies, law enforcement is increasingly integrating multiple methods that include geophysical technologies. There are numerous advantages for integrating geophysical technologies, such as side scan sonar and ground penetrating radar (GPR), with more traditional search methods. Overall, these methods decrease the time involved searching, in addition to increasing area searched. However, as with other search methods, there are advantages and disadvantages when using each method. For example, in instances with excessive aquatic vegetation or irregular bottom terrain, it may not be possible to discern a submersed body with side scan sonar. As a result, forensic personnel will have the highest rate of success during searches for submerged objects when integrating multiple search methods, including deploying multiple geophysical technologies. The goal of this paper is to discuss the methodology of various search methods that are employed for submerged objects and how these various methods can be integrated as part of a comprehensive protocol for water searches depending upon the type of underwater terrain. In addition, two successful case studies involving the search and recovery of a submerged human body using side scan sonar are presented to illustrate the successful application of integrating a geophysical technology with divers when searching for a submerged object.


Subject(s)
Immersion , Sound , Animals , Archaeology , Diving , Dogs , Forensic Sciences , Humans , Radar , Robotics , Signal Processing, Computer-Assisted
16.
J Forensic Sci ; 57(5): 1155-60, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22458801

ABSTRACT

Morphological traits of the posterior ilium are commonly used for sex determination in bioarcheological and forensic skeletal analysis. This study was designed to compare the classification correctness of standard scoring systems and measurements of the posterior ilium, including using logistic regression, to develop new formulae to predict sex. Metric measurements and morphological scores for the preauricular sulcus (PS), the elevation of the auricular surface, and the greater sciatic notch width were recorded for 97 males and 101 females of both European and African ancestry from the William M. Bass and Terry Collections. Correct classification of sex was high using individual traits such as the greater sciatic notch score (88.4%), the presence or absence of a PS (78.8%), and the scoring of a present PS as 1, 2, or 3 (100%). Furthermore, an equation combining multiple traits of the posterior ilium had a high classification of 94.9%.


Subject(s)
Ilium/anatomy & histology , Sex Determination by Skeleton/methods , Adult , Black People , Female , Forensic Anthropology , Humans , Linear Models , Male , Middle Aged , White People , Young Adult
17.
Forensic Sci Int ; 209(1-3): 64-9, 2011 Jun 15.
Article in English | MEDLINE | ID: mdl-21237591

ABSTRACT

Since ground-penetrating radar (GPR) has become a popular search option for clandestine graves, controlled research is essential to determine the numerous variables that affect grave detection. The purpose of this study was to compare GPR reflection profiles of a controlled grave containing a large pig carcass and a blank control grave at 6 months interment in a Spodosol, which is a common soil type in Florida. Data collection was performed in perpendicular orientations over the graves using both 500 and 250 MHz antennae. Since reflection profiles are used to make initial in-field assessments during a forensic search, it is important for controlled research to evaluate this imagery option. Overall, it was possible to detect the grave containing a pig carcass at 6 months interment that was buried in a Spodosol using both the 500 and the 250 MHz antennae. While the 500 MHz antenna provided more detail within the grave containing a pig carcass, including detecting a soil disturbance and the pig carcass, the 250 MHz antenna also provided excellent imagery. Either antenna would provide optimal results for the type of soil that was sampled. Furthermore, it may be possible to locate actual forensic graves in this soil type when no response from the body is noted, as there may be a discernable response from the disturbed soil within the grave shaft and a noticeable disruption of the spodic horizon. Finally, survey orientation may also affect detection. Since data collection performed in two perpendicular directions detected the pig carcass and the grave floor of the control grave, data collection for an actual search involving a body interred for a long postmortem interval should be performed in both directions when time permits.


Subject(s)
Burial , Electric Impedance , Radar , Animals , Forensic Anthropology , Geological Phenomena , Swine
18.
Forensic Sci Int ; 208(1-3): 18-24, 2011 May 20.
Article in English | MEDLINE | ID: mdl-21075570

ABSTRACT

Forensic personnel may face a daunting task when searching for buried weapons at crime scenes or potential disposal sites. In particular, it is common to search for a small firearm that was discarded or buried by a perpetrator. When performing forensic searches, it is recommended to first use non-invasive methods such as geophysical instruments to minimize damage to evidence and to the crime scene. Geophysical tools are used to pinpoint small areas of interest across a scene for invasive testing, rather than digging large areas throughout the site. Prior to this project, there was no published research that tested the utility of the conductivity meter to search for metallic weapons such as firearms and blunt and sharp edged weapons. A sample comprised of 32 metallic weapons including firearms, blunt and sharp edged weapons, and scrap metals was buried in a controlled setting to test the applicability of a conductivity meter for forensic searches. Weapons were tested at multiple depths and after data collection was performed for one depth, the weapons were reburied 5 cm deeper until they were no longer detected. Variables such as weapon size, burial depth, transect interval spacing (25 and 50 cm), and metallic composition were tested. All of the controlled variables influenced maximum depth of detection. For example, size was a factor as larger weapons were detected at deeper depths compared to smaller weapons. Metal composition affected maximum depth of detection as the conductivity meter detected items comprised of ferrous metals at deeper depths than non-ferrous metals. Searches for large buried items may incorporate a transect interval spacing of 50 cm but small weapons may be undetected between transects and therefore a transect interval spacing of 25 cm is recommended. Overall, the conductivity meter is a geophysical tool to consider when searching for larger-sized metallic weapons or to use in conjunction with an all-metal detector, particularly when searching for buried metallic evidence in obstructed areas.

19.
J Forensic Sci ; 56(5): 1289-95, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21554314

ABSTRACT

Forensic personnel generally use basic all-metal detectors for weapon searches because of their ease of use and cost efficiency. For ferromagnetic targets, an alternative easy to use and low-cost geophysical tool is a magnetic locator. The following study was designed to demonstrate the effectiveness of a common, commercially available magnetic locator in forensic weapon searches by determining the maximum depth of detection for 32 metallic forensic targets and testing the effects of metallic composition on detection. Maximum depth of detection was determined for 16 decommissioned street-level firearms, six pieces of assorted scrap metals, and 10 blunt or bladed weapons by burying each target at 5-cm intervals until the weapons were no longer detected. As expected, only ferromagnetic items were detected; weapons containing both ferromagnetic and nonferromagnetic components were generally detected to shallower depths. Overall, the magnetic locator can be a useful addition to weapon searches involving buried ferromagnetic weapons.

20.
Forensic Sci Int ; 195(1-3): 121-7, 2010 Feb 25.
Article in English | MEDLINE | ID: mdl-20036788

ABSTRACT

Incorporating geophysical technologies into forensic investigations has become a growing practice. Oftentimes, forensic professionals rely on basic metal detectors to assist their efforts during metallic weapons searches. This has created a need for controlled research in the area of weapons searches, specifically to formulate guidelines for geophysical methods that may be appropriate for locating weapons that have been discarded or buried by criminals attempting to conceal their involvement in a crime. Controlled research allows not only for testing of geophysical equipment, but also for updating search methodologies. This research project was designed to demonstrate the utility of an all-metal detector for locating a buried metallic weapon through detecting and identifying specific types of buried metal targets. Controlled testing of 32 buried targets which represented a variety of sizes and metallic compositions included 16 decommissioned street-level firearms, 6 pieces of assorted scrap metals, and 10 blunt or bladed weapons. While all forensic targets included in the project were detected with the basic all-metal detector, the size of the weapon and surface area were the two variables that affected maximum depth of detection, particularly with the firearm sample. For example, when using a High setting the largest firearms were detected at a maximum depth of 55 cm, but the majority of the remaining targets were only detected at a maximum depth of 40 cm or less. Overall, the all-metal detector proved to be a very good general purpose metal detector best suited for detecting metallic items at shallow depths.

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