Ghosting phenomenon in static and dynamic footprints in India and the United States

Ghosting is the phenomenon that exists when a footprint has a lighter area around the tip of one or more toes or a shadow-like area at the back of the heel. To date, ghosting has been considered primarily a finding of dynamic (walking) footprints, rather than static (standing) footprints. The prevalence of ghosting in static footprints is unknown, and research on its presence in static and dynamic footprints from the same participant is sparse, as are studies on its occurrence in different geographic populations. This study is among the first to evaluate the occurrence of ghosting in the static and dynamic footprints from a particular individual with participants in two geographic populations.A combination of both inkless and ink footprint collection systems were used to obtain a total of 206 bare footprints from 103 adult participants from the United States and India. The data comprised 103 static and 103 dynamic footprints.Ghosting occurred significantly in static footprints, though less frequently than in dynamic footprints. Ghosting in static footprints was seen most often at the first toe, followed by the third and second respectively. This aspect appeared least at the heel. In dynamic footprints, it occurred most at the first toe, followed by the second and fourth toes, and then the third toe and the heel. The prevalence of ghosting in footprints from the United States and India differed in their locations, notably at the first and second toes in the static footprints and at the heel in the dynamic footprints.     

The application of CT for 3D visualization of concealed bodies

In forensic radiology, computed tomography (CT) is often used as a medical imaging technique to identify the cause and manner of death of deceased victims of a possible crime. In this study, medical imaging is used to examine concealed bodies and packaging materials. Medical imaging techniques, mainly CT scan, were used to scan packaged or concealed bodies inside containers to identify clues and evidence indicating whether a crime might have been committed. Also, scene integrity and scene safety along with a systematic search for relevant evidentiary items value were considered.Eighteen concealed bodies that had been assessed using medical imaging techniques between 2010 and 2018 at the request of the Dutch National Police were selected. The file records of each case contained imaging data, a photographic record of the unpacking procedure, a list of all items and traces found in the package, and the forensic pathology report. The images were assessed with respect to the different aspects of the case and through a systematic approach.The packages included adult males, adult females, newborn infants, and animals. All human cases were related to criminal offences. In nine adult cases, evidence of a possible violent death could be determined using CT imaging. The cause of death in newborn infants, however, could not be determined. In cases of dismemberment, the completeness of the body could be determined by CT imaging, and the cutting surfaces of bones could be matched on CT images. Regarding scene safety and integrity, in this study all relevant macroscopic items were detected on the CT images.The CT-scans were supplemented with fiduciary markers to better map CT data with the real objects. This information in combination with 2D and 3D images provided the forensic investigator with information on how to unwrap the package layer by layer and help determine different types of packaging materials. Different textiles could not always be identified. The orientation of the body within the packages was provided in all cases, and advice could be given on the optimal approach to access the contents. The overall detection rate of items was 78%.This is one of the first studies to illustrate the contribution of medical imaging, specifically CT scan, to the analysis of concealed bodies and packaging materials prior to unpacking. This demonstrates its contribution to a systematic approach of the investigation by ensuring the safety and health of the investigator while documenting and maintaining the integrity of the crime scene. Imaging also provides information that can be helpful to determine whether a crime might have been committed and reducing the risk of damaging a concealed body. Medical imaging also provides the forensic investigator with information to draw up a workplan prior to unpacking, minimising loss of evidence and determining whether different forensic specialists (e.g., digital or DNA) are needed. It is therefore strongly recommended to use medical imaging, especially CT scanning, before opening a package containing a concealed body.     

Inter-observer error for area of origin analysis using FARO Zone 3D

In a bloodletting incident, the area of origin (AO) of an impact bloodstain pattern is crucial when establishing the sequence of events. The use of laser scanners and other three-dimensional (3D) technologies to document and analyse bloodstains have been the subject of previous papers, especially where AO analysis is concerned. FARO Zone 3D (FZ3D) is a relatively new software programme that can be used for bloodstain AO analysis. FZ3D requires a greater understanding of inter-observer errors associated with AO. This study looked at the inter-observer variation between 21 examiners when repeatedly calculating the AO six times for a single impact pattern on a plain white wall. An impact rig which consisted of a spring tension arm was positioned and fixed 45 cm from the X wall (right wall), and 45 cm from the Y wall (left wall). This experimental design resembles an impact blow for a bloodletting event. The AO was unknown to all examiners, making it a blind study. The collected results were documented in a Microsoft Excel datasheet and later analysed. From previous literature, a 30 cm acceptable allowance was utilised for AO analysis; however, there is currently no accepted standard error for this type of analysis. The overall total 3D mean error for all examiners was 5.62 cm. The maximum error for any one impact analysis was 24.27 cm. The variation of the data, which was collected by all examiners, was documented as X = 1.14 cm, Y = 1.24 cm, Z = 1.68 cm, and the total 3D error = 2.28 cm. The total 3D error for any one examiner and the variance between examiners did not exceed the 30 cm acceptable allowance utilised in previous literature.     

Allele frequencies for nine STR loci (D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) in the Italian population

Genotype and allele frequencies for STR loci D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820 were investigated in 289 unrelated Italian Caucasian individuals from the North and South regions. After co-amplification by polymerase chain reaction, automatic DNA profiling of these nine STR loci was performed by ABI PRISM((R)) 310 DNA Genetic Analyzer. For each locus, statistical parameters for forensic and paternity purposes were then calculated; the combined power of discrimination and the combined power of exclusion of all nine loci were 0.9999999999917 and 0.99992 for the Northern population and 0.9999999999921 and 0.99991 for the Southern population.