Child abduction murder: the impact of forensic evidence on solvability

This study examined 733 child abduction murders (CAMs) occurring from 1968 to 2002 to explore the influence of forensic evidence on case solvability in CAM investigations. It was hypothesized that the presence of forensic evidence connecting the offender to the crime would enhance case solvability in murder investigations of abducted children. This study examined the impact of CAM of different types of forensic evidence and the impact of the summed total of forensic evidence items on case solvability by controlling for victim age, victim race, victim gender, and victim-offender relationship. Time and distance theoretical predictors were also included. Binomial logistic regression models were used to determine whether forensic evidence was a critical solvability factor in murder investigations of abducted children. This research indicated that, while forensic evidence increased case solvability, the impact of forensic evidence on solvability was not as important as other solvability factors examined.     

Evaluation of gastrointestinal cancer tissues as a source of genetic information for forensic investigations by using STRs

Malignant tissue samples may sometimes be the only source of biological material for forensic investigations, including identification of individuals or paternity testing. However, in use of such samples, uncertainties due to microsatellite instability (MSI) and loss of heterozygosity (LOH) often associated with neoplasias may be encountered. In this study, we have analysed the applicability of autosomal tetranucleotide short tandem repeat (STR) markers, which are routinely used in forensic analysis, to gain genetic information. MSI and LOH were analysed in 41 surgically removed gastrointestinal cancer specimens and the adjascent non-cancerous tissue marginals. The cancer specimens showed great variability in their genetic phenotypes due to MSI or LOH, with only 32% being microsatellite-stable. Of the 15 autosomal STR loci analysed, only TH01 had no MSI-type alteration in these samples. The loci most frequently affected by MSI were D8S1179, D21S11, D18S51 and D19S433 (MSI in 15-17% of cases). LOH-type alterations were observed at all of the loci, including the amelogenin locus used for sex determination. The highest LOH frequency was found at locus D18S51 (27%). The genetic alterations at the marker loci may indicate false homozygosity or heterozygosity, and false gender may result from erroneous deduction of DNA profiles. Therefore, typing of autosomal STRs from malignant tissues in forensic settings warrants careful interpretation of MSI and LOH results together with microscopic analysis of a tissue specimen. Results by two commercially available and widely used forensic DNA profiling kits used here were comparable.     

Atomic force microscopy as a biophysical tool for nanoscale forensic investigations

The atomic force microscope (AFM) has found its way to the arsenal of tools available to the forensic practitioner for the analysis of samples at the nano and microscales. As a non-destructive probing tool that requires minimal sample preparation, the AFM is very attractive, particularly in the case of minimal or precious sample. To date, the use of the AFM has primarily been in the arena of imaging where it has been complementary to other microscopic examination tools. Forensic applications in the visual examination of evidence such as blood stains, questioned documents, and hair samples have been reported. While a number of reviews have focused on the use of AFM as an imaging tool for forensic analyses, here we not only discuss these works, but also point to a versatile enhancement in the capabilities of this nanoscale tool – namely its use for force spectroscopy. In this mode, the AFM can determine elastic moduli, adhesion forces, energy dissipation, and the interaction forces between cognate ligands, that can be spatially mapped to provide a unique spatial visualization of properties. Our goals in this review are to provide a context for this capability of the AFM, explain its workings, cover some exemplary works pertaining to forensic sciences, and present a critical analysis on the advantages and disadvantages of this modality. Equipped with this high-resolution tool, imaging and biophysical analysis by the AFM can provide a unique complement to other tools available to the researcher for the analysis and characterization of forensic evidence.     

An already archived latent fingerprint as a DNA source for STR typing in a murder case

Former studies have shown that even a single skin contact, resulting in a latent fingerprint, can transfer enough DNA for genetic analysis. However, up to now latent fingerprints have usually not been used for DNA typing. In the present case the smeared trace of a hand was found in the suspect's car and archived. As it could not be evaluated in a classical manner, the evidence had to be examined by molecular genetic methods. DNA was extracted and typed in five different STR loci. Based on the yielded results, the significance of the findings is discussed.     

Use of forensic investigations in anti-doping

The fight against doping is mainly focused on direct detection, using analytical methods for the detection of doping agents in biological samples. However, the World Anti-Doping Code also defines doping as possession, administration or attempted administration of prohibited substances or methods, trafficking or attempted trafficking in any prohibited substance or methods. As these issues correspond to criminal investigation, a forensic approach can help assessing potential violation of these rules. In the context of a rowing competition, genetic analyses were conducted on biological samples collected in infusion apparatus, bags and tubing in order to obtain DNA profiles. As no database of athletes' DNA profiles was available, the use of information from the location detection as well as contextual information were key to determine a population of suspected athletes and to obtain reference DNA profiles for comparison. Analysis of samples from infusion systems provided 8 different DNA profiles. The comparison between these profiles and 8 reference profiles from suspected athletes could not be distinguished. This case-study is one of the first where a forensic approach was applied for anti-doping purposes. Based on this investigation, the International Rowing Federation authorities decided to ban not only the incriminated athletes, but also the coaches and officials for 2 years.     

Some further evidence on imprisonment vs. the death penalty as a deterrent to murder

Law and Human Behavior - The research reported here extends an earlier investigation (Bailey, 1977) on the deterrent effect of imprisonment versus the death penalty for murder. As a result of some...     

Intoxication as a defence to murder in Seychelles

In Seychelles, the mens rea of murder can be established, as an alternative to an intention to cause death or grievous harm, on the basis of the defendant’s ‘knowledge’ that the act or omission causing death will probably cause death or grievous harm. However, a defendant is only allowed to plead intoxication as a defence where it had become impossible for him to form the necessary ‘intention’ due to intoxication. This article highlights the difficulties in the application of the defence of intoxication to cases where the mens rea for murder is based purely on a defendant’s ‘knowledge’. In analysing the defence of intoxication in Seychelles in cases of murder, the article examines the position under English and Australian law.     

Cell free DNA as a component of forensic evidence recovered from touched surfaces

In the course of a criminal investigation, DNA is often recovered from items that have been handled by an individual. Whilst there have been studies investigating the propensity of different individuals to deposit DNA, little is known about the factors involved in the transference of DNA through touch. This investigation seeks to clarify some of the underlying processes involved in DNA transfer, as to better understand the significance of so-called “touch DNA” evidence (tDNA). It was shown that an average yield of 11.5 ng of DNA could be recovered from 1 mL cell-free sweat samples leading to the hypothesis that cell-free nucleic acids (CNAs) of a suitable length for standard DNA profiling are transferred during handling/touching items. A method of standardization of tDNA deposition was developed to overcome the significant sample to sample variability in DNA levels characteristic of tDNA samples. The glass bead method allowed the creation of identical tDNA sample sets, thus permitting direct comparisons to be made in the efficiency of various extraction methods. Extraction methods designed to optimize CNA recovery from touched articles resulted in comparable yields in a general population study, however the methods resulted in a twofold increase in DNA yields from touched items touched by individuals with sweaty hands. These results suggest that the CNA component of touched surfaces should be included to maximize profiling success of tDNA.     

法医尸检和现场重建分析在认定疑难杀人案中的作用

法医尸体检验结果结合案情与现场情况进行现场重建分析,是公安部门的法医应具有的基本功,对命案的侦查和审判具有十分重要的意义,实例报告尚不多,现报告如下.     

Two items of evidence, no putative source: an inference problem in forensic intelligence

Intelligence analysts commonly associate cases on the basis of similarities found in compared characteristics of scientific evidence. The present paper studies some of the inferential difficulties associated with such operations. An analysis is proposed that breaks down the reasoning process into inference to common source, and inference to case linkage. The former requires an approach to the difficulty associated with evaluating the similarities of items of evidence from different cases with no putative source being available. The latter requires consideration to be given to the relevance of evidence. Throughout the paper, probability theory is used to describe the nature of the proposed inferences. Graphical models are also introduced with the aim of providing further insight into the dependence and independence relationships assumed to hold among the various propositions considered. Notions from decision theory are used to discuss ways in which intelligence analysts may assist investigators in deciding whether or not cases should be considered as linked.     

Teeth as a source of DNA for forensic identification of human remains: A Review

Teeth and bones are frequently the only sources of DNA available for identification of degraded or fragmented human remains. The unique composition of teeth and their location in the jawbone provide additional protection to DNA compared to bones making them a preferred source of DNA in many cases. Despite this, post-mortem changes in the structure and composition of teeth, and the location and diagenesis of DNA within them are poorly understood. This review summarises current knowledge of tooth morphology with respect to DNA content and preservation, and discusses the way in which post-mortem changes will affect the recovery of DNA from teeth under a range of commonly used extraction protocols. We highlight the benefits and pitfalls of using specific tooth tissues for DNA extraction and make recommendations for tooth selection and sampling that will maximise DNA typing success. A comprehensive understanding of tooth structure and an appreciation of the relationship between DNA and mineralized tissues in post-mortem teeth are critical for optimal sample selection. More informed sampling methods that target specific tooth tissues will increase the likelihood of successful genetic analysis and allow for efficient and timely missing persons case work and disaster victim identification response.     

The routine use of C-reactive protein in forensic investigations

In clinical medicine, C-reactive protein (CRP) is extensively used as a general marker for immune system activation, and post-mortem applicability has been established [M.Q. Fujita, B.L. Zhu, K. Ishida, L. Quan, S. Oritani, H. Maeda, Serum C-reactive protein levels in postmortem blood-an analysis with special reference to the cause of death and survival time, Forensic Sci. Int. 130 (2002) 160-166; L. Uhlin-Hansen, C-reactive protein (CRP), a comparison of pre- and post-mortem blood levels, Forensic Sci. Int. 124 (2001) 32-35]. We have analysed the routine use of CRP in non-selected cases. Scarcity of blood available for analysis is a common problem in forensic investigation, and in response to this we have developed a method using liver as a source. In 50 consecutive autopsy cases, we have evaluated method, validated results and discussed their interpretation. In three cases the analysis was not possible. For each of the remaining cases (n=47) we have analysed whole blood, serum and/or liver samples. 57% (n=25) had serum CRP > 10 mg/L. Serum levels were higher than in whole blood or liver. CRP levels in serum and whole blood samples were stable in more than one month after death, making storage for later analysis possible. Liver levels peaked at one week, but after one month putrefaction was obvious. CRP levels were independent of the post-mortem interval. The use of liver as a source has not yet been described in literature. Our results in liver samples correlate well with plasma results, and liver is a good post-mortem alternative when blood is not available. We conclude that CRP measurements are easy, viable and inexpensive in a forensic setting, and that the number of cases with CRP elevation is high in a non-selected forensic material. In cases of doubt, marked elevation of CRP is an indicator of natural mode of death, and in cases of trauma, it indicates vital reaction. It can be used as a pre-autopsy screening, leading to a more extensive search for diseases not easily diagnosed, such as sepsis or ketoacidosis.     

Scanning electron microscopic analysis of skin resolution as an aid in identifying trauma in forensic investigations

The forensic investigator is frequently confronted with cases that present with wounds and blunt force trauma. Presently, the forensic investigator depends upon previous experience and further investigative deduction of the crime scene to analyze these injuries. Although not readily apparent to the naked eye, many skin tissue injuries can be visualized with scanning electron microscopy (SEM). This study was designed to establish skin trauma resolution using SEM in various skin preparations. Tissue trauma was induced on leather, preserved skin, fresh skin, and living skin using dies of varying thread size. Calibrated pressure forces in pounds per square inch (psi) were applied and impressions made using vinyl polysiloxane. Positive replicas of the tissues were prepared for SEM using isocyanate resin. After sputter coating the cast with 35 nm of gold-palladium, electron micrographs were generated using a Jeol JSM-5310LV scanning electron microscope. To establish resolution, thread widths of 52, 104, and 208 threads per inch (tpi) and trauma forces of 150, 200, and 250 psi were used to produce the impressions. Microgrooves that were identified on the die threads were analyzed. The optimum pressure for resolution studies was 150 psi using the 52 tpi die on the leather sample (4.67 +/- 0.88 microm, p = 0.046 and 0.025, respectively, by ANOVA). The resolution was compared to that of leather using preserved, fresh, and living skin. The resolution in preserved and fresh skin was less than for leather (9.00 +/- 1.73 and 10.5 +/- 4.5 versus 4.67 +/- 0.88 microm, p = 0.09 and p = 0.20, respectively). Living skin resolution was 3 microm at 52 tpi and 100 psi. Various implements of blunt force trauma were also examined using the leather sample. Time after trauma resolution was examined at 0 (3 microm), 5 (6 microm), 10 (8 microm), and 20 (9 microm) min in living tissue. A comparison between the microgrooves on the die replicas and the tissue trauma impressions revealed striking agreement for both linearity and resolution. Analysis of the microgrooves suggests that discrete morphological characteristics are seen in skin tissue traumas. This method could expand the tools available for the forensic investigation of blunt force trauma.     

The legal aspects of corporate computer forensic investigations

The use of computer forensics was previously limited mainly to law enforcement agencies. However, UK organisations are increasingly undertaking computer forensics activities for incidents such as fraud, money laundering, accessing or distributing indecent images, harassment, industrial spying and identity theft amongst others. In this paper we examine the legal aspects of UK corporate computer forensic investigations.     

Immunohistochemical analysis of forensic evidence from a double homicide

We report the use of immunohistochemical staining for analysis of forensic evidence from a double homicide. A 38-year-old woman and her 7-year-old daughter were murdered by multiple blows to the head and face with a tomahawk, resulting in multiple fragments of brain tissue scattered about the murder scene. The victims' husband and father was the main suspect, who maintained that he was out of town on business during the evening of the murders. However, a shirt taken from the suspect's car on the morning after the murders (secured by the police before the suspect visited the murder scene) was found to have two small stains. DNA analysis on the stains showed the presence of the deceased wife's DNA, and immunohistochemical stains on shirt fragments conclusively documented the presence of deep central nervous system tissue, providing the critical piece of evidence needed to arrest and prosecute the suspect. This report demonstrates that shirt or similar cloth fragments can be processed into paraffin blocks and subsequently immunostained to search for and classify types of tissue fragments that may be present on the fabric.     

Suicide disguised as murder: a dimension of Munchausen syndrome

This case study reports on a suicide made to look like murder. The case highlights the issue of false claims of criminal victimization and suggests the need for a reexamination of the dynamics of factitious allegations of criminal victimization. Factitious complaints of mental or physical illness are typically self-reported to psychiatric or medical authorities. This paper illustrates a different kind of phenomenon: one in which an injury or disorder is brought to medical attention by way of the police, who report the death or injury as arising from criminal victimization.     

The right to a fair trial as a conceptual framework for digital evidence rules in criminal investigations

Digital evidence and digital forensics have a significant impact on criminal investigation. This requires an examination if the fair trial principle remains sound in the new domain.In this paper the right to a fair trial in Art. 6 ECHR and its interpretation in case law is analysed in order to clarify its connection to evidence law and its specific application to the investigation stage of criminal proceedings. It is argued that the principle implicitly enshrines a framework for the development of universal evidence rules . Derived are two-groups of evidence rules: equality of arms based and presumption of innocence based. For each group specific challenges in the digital investigation are outlined and discussed in the context of a new governance model for digital evidence.