Forensic Science Investigations Research Articles

Environmental and criminal geoforensics: an introduction

Many subdisciplines within the Earth Sciences make use of either geophysical instruments to investigate the subsurface environment or use analytical methods to determine the origin, or provenance, of geological materials. These same instruments and analytical methods can be used either directly, or adapted to suit, the acquisition of data that pertain to a wide range of forensic science investigations. Such approaches, as discussed below, are generally not new but, in recent years, there has been a significant resurgence globally in the application of geological and geophysical methods to aid forensic investigations. Traditionally, such methods were used in forensic investigations related to serious criminal cases such as terrorism, murder, abduction and serious sexual assaults, and to a lesser extent in the investigation of cases of fraud and theft. But with increasing concern into the environmental impact of human activity, with the release of contaminants into the atmosphere, hydrosphere and lithosphere, and their potential uptake into the biosphere, there has been an increased amount of environmental legislation. In turn, there has commonly been an increase in the costs associated with the legal discharge or disposal of wastes. Consequently, it is unsurprising that the illegal discharge and disposal of wastes has also increased. Identifying the distribution, impact and source of such waste materials can, in part, be addressed through the application of geological techniques, in much the same way as used traditionally, for example, in the investigation of murder cases. The diversification of the use of geological techniques into the investigation of environmental crime will, potentially, significantly increase the range of investigations in which geologists may be asked to assist but will also lead to a new array of research questions to be addressed, hence the need for this Special Publication. In this short introduction, the aim is to place the current work into its broad historical context and summarize the key findings from the papers presented within this volume. The papers within this Special Publication were presented at two separate conferences in 2010: the Third International Soil Forensics Conference held at Long Beach California USA and organized by the SFI Group; and a conference on Environmental and Criminal Forensics, organized by the Forensic Geoscience Group of the Geological Society of London, and held at Burlington House, London, in December 2010.

"Beating the Devil's Game: A History of Forensic Science and Criminal Investigation"

"Beating the Devil's Game: A History of Forensic Science and Criminal Investigation"

Large Scale Simulation for Education in Forensic DNA Science

Forensic science education is a rapidly expanding field with several universities adding degrees in many forensic science disciplines. Concurrently, with this expansion is a new push for forensic science education in the secondary schools. This generation of students is also very adept at computer generated environments. The logical progression is therefore to provide students and instructors with a simulated environment to immerse students into forensic science investigations. The Island of Tir Ebensëa is a developing system that generates a large scale population and forensic scenarios and places the students as the investigators. Students are provided with a scenario and then generate queries to gain information about the people involved in the case. They can then draw conclusions about the scenario and compare these conclusions to the known answer. The simulation is available to educational institutions.

ISFG: Recommendations regarding the use of non-human (animal) DNA in forensic genetic investigations

The use of non-human DNA typing in forensic science investigations, and specifically that from animal DNA, is ever increasing. The term animal DNA in this document refers to animal species encountered in a forensic science examination but does not include human DNA. Non-human DNA may either be: the trade and possession of a species, or products derived from a species, which is contrary to legislation; as evidence where the crime is against a person or property; instances of animal cruelty; or where the animal is the offender. The first instance is addressed by determining the species present, and the other scenarios can often be addressed by assigning a DNA sample to a particular individual organism. Currently there is little standardization of methodologies used in the forensic analysis of animal DNA or in reporting styles. The recommendations in this document relate specifically to animal DNA that is integral to a forensic science investigation and are not relevant to the breeding of animals for commercial purposes. This DNA commission was formed out of discussions at the International Society for Forensic Genetics 23rd Congress in Buenos Aires to outline recommendations on the use of non-human DNA in a forensic science investigation. Due to the scope of non-human DNA typing that is possible, the remit of this commission is confined to animal DNA typing only.

An Inquiry-Based Contextual Approach as the Primary Mode of Learning Science with Microcomputer-Based Laboratory Technology

Science instruction can be designed to be laboratory-data driven. We report on an investigation of the use of thematic inquiry-based tasks with active incorporation of mathematics, science, and microcomputer-based laboratory technology in standards-correlated activities that enhanced learning experiences. Activities involved students in two major contexts: forensic science investigations and environmental science issues. The core of the project consisted of an analysis of students' proficiency in dealing with discipline-specific content, and of their development of critical thinking process skills. Significant gains were observed in both content proficiency and improvement on critical thinking skills, most noticeably those involving meta-cognitive processes. An interesting and unexpected feature of tool use emerged from the data that provides exciting opportunities for further research. The results provide evidence that such an instructional approach can have a dramatic impact on the development of students' mastery of content and laboratory performance measures of the science material that they encounter.

Intelligence-led crime scene processing. Part II: Intelligence and crime scene examination

A better integration of the information conveyed by traces within intelligence-led framework would allow forensic science to participate more intensively to security assessments through forensic intelligence (part I). In this view, the collection of data by examining crime scenes is an entire part of intelligence processes. This conception frames our proposal for a model that promotes to better use knowledge available in the organisation for driving and supporting crime scene examination. The suggested model also clarifies the uncomfortable situation of crime scene examiners who must simultaneously comply with justice needs and expectations, and serve organisations that are mostly driven by broader security objectives. It also opens new perspective for forensic science and crime scene investigation, by the proposal to follow other directions than the traditional path suggested by dominant movements in these fields.

Recent Developments on the Microstructural Effects Caused by Small-Charge Explosions in FCC Alloys

Metals exposed to small charge explosions, even in absence of overall deformation, show characteristic and permanent microstructural features, that can be related to blast wave properties, e.g. to the charge mass and the charge-to-target distance. In particular, Face Centered Cubic (FCC) alloys with low stacking fault energy may exhibit mechanical twinning due to the high strain rate caused by an explosion, even if in slower processes they mainly deform by slip. In some forensic science investigations, these crystallographic modifications, and particularly the occurrence of twinning, may be among the few remaining clues of a small charge explosion, and may be useful to hypothesize the nature and location of the charge. A wide experimental campaign was performed to correlate the blast wave properties with the ensuing modifications of FCC metal targets, and to investigate the microscopic deformation mechanisms leading to these modifications. In particular, it was attempted to identify the threshold conditions (charge-to-target distance, charge mass, and hence applied stress) that yield barely detectable microstructural modifications, and to study the transition from slip to twinning. FCC metal alloys, with low (α-brass, stainless steel), intermediate (copper, gold alloy), or high (aluminum alloy) stacking fault energy, were exposed to blast waves (caused by 50 or 100 g plastic explosive charges located at increasing charge-to-target distances) and then analyzed by X-ray diffraction, optical microscopy, scanning electron microscopy, and electron backscattered diffraction imaging. A comprehensive review of the most significant findings of the whole research, together with theoretical considerations on the slip and twinning deformation mechanisms, is here presented.

Establishing the mitochondrial DNA D‐loop structure of Columba livia

The complete mitochondrial DNA D-loop structure of pigeon (Columba livia) was established in this study. A strategy of amplifying three partial fragments of the D-loop and then combing the three fragments to cover the full length of the D-loop was adopted. Ten samples from pigeons were collected and were successfully amplified and sequenced. Repetitive sequences of a VNTR and an STR were both observed at the 3'-end of D-loop region. DNA sequence data revealed polymorphic sequences including indels, SNP, VNTR and STR within the D-loop. The size of the D-loop ranged from 1310 to 1327 bp from the initiation site of D-loop to the site immediately upstream of the repeat sequences depending upon the number of insertions or deletions. Each sample could be distinguished based on four genotyping procedures; being indels, SNPs, VNTRs and STRs. The polymorphic nature of the D-loop can be a valuable method for maternal identification and genetic linkage of pigeon in particular forensic science investigations.

Development of Two Murine Monoclonal Antibodies Recognizing Human nG1m(a)-Like Isoallotypic Markers

Antigenic determinants of immunoglobulin molecules are categorized into three groups: idiotypes, isotypes, and allotypes. An isoallotype is defined as an isotypic determinant in one or more subclasses and an allotype in another subclass of a given isotype. The isoallotype nG1m(a), formerly called non-a, is an allotype located on human IgG1 molecules lacking the G1m(a) allotype. This marker, however, is also detectable on all human IgG2 and IgG3 molecules. Anti-isoallotypic antibodies are useful tools for structural studies of immunoglobulins, forensic science, and epidemiological demographic investigations. In this study, two murine monoclonal antibodies (MAbs) recognizing nG1m(a)-like epitope(s) were generated against a human IgG myeloma protein. These MAbs are produced by hybridoma clones (4F18B12 and 6F18D1) obtained by fusion of SP2/0 myeloma cells with splenocytes from BALB/c mice immunized with heavy chain of a human IgG3 myeloma protein. These MAbs reacted with Fc, but not Fab fragment of the immunizing IgG3 paraprotein. Specificity of the MAbs was further analyzed using a panel of purified myeloma proteins and polyclonal IgG3, including IgG1 (n = 9), IgG2 (n = 4), IgG3 (n = 8), and IgG4 (n = 6) subclasses. Our results demonstrated that these MAbs reacted with linear epitope(s) located on heavy chain of all IgG2 and IgG3 molecules tested and some paraproteins of IgG1 subclass, but none of the IgG4 molecules. So these MAbs seem to recognize nG1m(a)-like isoallotypic marker. These MAbs showed no cross-reactivity with serum of other species tested. Both MAbs belonged to IgG1 subclass with affinity constants of 4.5 x 10(9) mol(-1) (4F18B12) and 3.46 x 10(9) mol(-1) (6F18D1), respectively. These MAbs might be used as a tool to detect nG1m(a) + IgG molecules.

A technique for the quantification of human and non-human mammalian mitochondrial DNA copy number in forensic and other mixtures

The number of mitochondria per cell varies by cell type and the number of mitochondrial DNA (mtDNA) genomes varies per mitochondrion. Biological samples from unknown species are encountered frequently in forensic science investigations and are often contaminated with human mtDNA making analysis difficult. Currently, no techniques to quantify non-human mtDNA are available. We report on a method to accurately quantify, sensitive to 100 copies (1.7 fg), mtDNA from human and non-human sources when present as a mixture. The test developed uses the cytochrome b (cyt b) and the ribosomal 12S genes on the mitochondrial genome. Universal and human specific fragments of similar size are amplified and quantified using SYBR Green. We validate the test with 24 human samples and 27 non-human mammalian samples. The human fraction of a sample can then be subtracted from the universal fraction for an accurate estimation of non-human mtDNA copy number.

Diagnostic Raman spectroscopy for the forensic detection of biomaterials and the preservation of cultural heritage

This paper reviews the contributions of analytical Raman spectroscopy to the non-destructive characterisation of biological materials of relevance to forensic science investigations, including the sourcing of resins and the identification of the biodegradation of art and archaeological artefacts. The advantages of Raman spectroscopy for non-destructive analysis are well-appreciated; however, the ability to record molecular information about organic and inorganic species present in a heterogeneous specimen at the same time, the insensitivity of the Raman scattering process to water and hydroxyl groups, which removes the necessity for sample desiccation, and the ease of illumination for samples of very small and very large sizes and unusual shapes are also apparent. Several examples are used to illustrate the application of Raman spectroscopic techniques to the characterisation of forensic biomaterials and for the preservation of cultural heritage through case studies in the following areas: wall-paintings and rock art, human and animal tissues and skeletal remains, fabrics, resins and ivories.

Unusual results due to transfused blood

During a murder enquiry, the forensic science investigation used PGM and EAP blood grouping systems and detected a mixture of blood on the deceased's jacket. The blood groups matched those of the deceased and accused. The results of DNA analysis, however, proved that only a single source of DNA, matching the deceased, was present. Supplementary information relating to the transfusion of the individual whilst still wearing his clothing led the authors to conclude that a mixture of transfused blood and the individual's own blood had effused from his body via a stab wound, and onto his clothing.

Application of Mitochondrial DNA for Cytochrome b Gene to Species Identification in Forensic Science

The variation of mitochondrial cytochrome b gene(cyt b) has been a rich source of phylogenetic inference in a wide range of animal species. In the present study, PCR-RFLP pattern of cyt b were compared to identify species of animals for forensic science investigation. Using total DNA isolated from blood of five human individuals, eight species of mammal(baboon, cow, pig, dog, cat, bear, deer and raccoon dog) and two species of bird(chicken and wild duck), cyt b were analyzed by using the PCR method. Using the primers designed for cyt b by Chikuni et al. (1994), cyt b was amplified to obtain about 700bp fragment from seven mammals(human, baboon, cow, pig, cat, bear and deer) and two birds (chicken and wild duck). The PCR products were digested with two restriction endonucleases(Hae III or Hinf I), and the difference was observed among mammals and birds as PCR-restriction fragment length polymorphism (RFLP). PCR-PFLP patterns with Hinf I of human differed from other animals. In this study, nine animal species could be simply identified by this method. DNAs from some spiecies were not able to be amplified probably depending on a mismatch of primers. The polymorphism in cyt b was a useful tool for species identification in a forensic casework. Further study is needed to apply this method to a forensic casework.

Identification of lipstick smears by fluorescence observation and purge-and-trap gas chromatography

Nondestructive methods of forensic identification were tested on 174 samples of lipsticks from 11 Japanese cosmetics manufacturers. Sample color was observed under white light and fluorescence was observed using light at wavelengths of 350, 445 and 515 nm. Purge-and-trap gas chromatography was used as a direct analytical technique for lipstick smears without any pretreatment. No interference was observed in chromatographic patterns when substrates such as wool, cigarette tips or filter paper were analyzed together with lipstick. Combining all of the techniques studied allowed us to discriminate between 15,038 pairs of samples out of 15,051. We conclude that this method is suitable for identification of trace amounts of lipsticks for forensic science investigation.

Ideology and forgery: The Deventer bones

Forensic-science investigations have shown that the engravings on the bones from the Deventer collection of the National Museum of Antiquities in Leiden, The Netherlands, appear to be very suspect. Neither the pictorial engravings of Bronze-Age or Carolingian style, nor of the runes, show any signs of weathering or decomposition. Research into the Dutch archives has also indicated the ideological motivation for these apparent forgeries and that the majority of the engravings seem to have been copied directly from a Nazi magazine, ‘Hamer’, in the early 1940s. In order to resolve definitely the question of whether the engravings are real or faked, we have measured the radiocarbon age of the bones themselves. These results showed that the oldest bone dates to the Middle Ages and the others are less than a few hundred years old. This confirmed that the engravings cannot be as old as they were purported to be. This noteworthy case of forgery which had presupposed a certain ideology should be of interest to the forensic scientist.

The Identification of Maternity in an Unusual Pregnancy-Related Homicide

A recent bizarre homicide which culminated in the delivery of a live-born infant necessitated careful determination of true maternal origin. A 23-year-old pregnant woman was abducted, subdued, strangled, and delivered of a term infant by a crude Cesarean section. The infant was stolen and subsequently presented to physicians by a woman posing as the mother. Methods used to help confirm the surviving infant's parentage involved red cell antigen and enzyme system evaluations as well as immunoglobulin allotyping, which ultimately proved to be the most effective serologic test performed. The forensic science investigation of this unusual case also used bite mark analysis and patterned injury interpretation. Immunoglobulin allotyping is specifically discussed as a forensic serology test which is currently available and particularly applicable in cases involving parentage determination.

The application of electrostatics in forensic science

During forensic science investigations, it is necessary to segregate materials of interest such as minute fragments of paint and glass from other debris recovered from clothing. Such debris typically consists of short fibres, particulate metal, sand, soil, etc. This paper describes the development of electrostatic techniques which principally include: 1. (i) A high resolution electric field probe to identify, by virtue of their electrostatic properties, the individual fibres or particles encountered in a forensic investigation. 2. (ii) The resolution of mixed debris into constituent components by manipulation in a precisely controlled variable frequency electric field. The paper goes on to describe the development of a novel prototype separator which by using a combination of electrostatic and mechanical forces enables the forensic scientist to achieve rapid and efficient recovery of small fragments of household and vehicle paint from mixed forensic debris.

An Assessment of the Value of Blue, Red, and Black Cotton Fibers as Target Fibers in Forensic Science Investigations

Abstract Color is the primary characteristic used for comparing cotton fibers. Problems arising because of considerable intrasample variation may cause difficulty in assessing the matching of cotton fibers in a casework situation. Because of the number of dye classes used on cotton fibers, dye extraction and examination by thin-layer chromatography are more problematical than with other fiber types. This necessitates greater reliance on microspectrophotometry and fluorescence microscopy for dye comparison. Fibers from blue denim cannot generally be discriminated and are regarded as having little evidential value. Little or no published data exist on the evidential value of cotton fibers of other colors. This study was designed to assess the value of nondenim blue, red, and black cotton fibers as evidence. Of each color 46 samples were chosen at random (giving a total of 1035 comparisons per color). The number of matching pairs was established after using comparison microscopy, microspectrophotometry, and fluorescence microscopy. Some blue denim cotton fibers were also examined. Complementary chromaticity coordinates were computed for all samples. The results show that, provided adequate techniques are used to compare nondenim blue, red, and black cotton fibers, the chance of finding pairs with matching dyes by coincidence is low despite considerable color overlap. Black cotton fibers represent poorer value as evidence than either nondenim blue or red cotton fibers.

On the Application of Metallurgical Techniques to Forensic Sciences

Abstract Metallurgical techniques, such as metallographic examination, are seldom reported as being used in forensic science investigations. In these cases, most findings related to the metal's nature rely on visual and chemical examinations. The potential of applying metallurgical techniques to forensic science investigations is illustrated by means of two case histories. The information needed to establish a link between different pieces of metal is obtained from a metallographic examination of the metal's microstructure which reflects its thermomechanical history. It is shown that this kind of information is unique and cannot be obtained by applying conventional techniques such as chemical analysis. It is therefore concluded that metallurgical techniques can successfully complement other scientific techniques commonly employed in the forensic science context.

Simultaneous thermogravimetry/mass spectrometry: a new TG-MS interface for forensic science applications

A newly developed TG-MS-interface of the capillary type for forensic science applications is presented. The performance is demonstrated by two examples. The time resolved analysis of the decomposition of poly-(t.-butylmethacrylate) shows the behavior of the apparatus for the medium molecular mass range. Sensitivity and transient response especially for higher molecular masses up to m/z 450 have been tested by a transfer experiment with the commercial UV-absorber Tinuvin 234. The results demonstrate clearly that the interface meets the requirements of forensic science investigations.