Characterization and differentiation of aluminum powders used in improvised explosive devices – Part 1: Proof of concept of the utility of particle micromorphometry

Aluminum (Al) powders are commonly used in improvised explosive devices as metallic fuels, a component of explosive mixtures. These powders can be obtained readily from industrial‐scale and consumer products, and produced using unsophisticated “kitchen chemistry” techniques. This research demonstrates the potential of automated particle micromorphometry for comparisons between known source and questioned Al powders recovered from IEDs, as well as for insight into the method of Al powder manufacture. Al powder samples were obtained from legitimate manufacturers, and 56 samples were produced “in‐house” from Al‐containing spray paints and ball‐milled Al foils. Transmitted light microscope images of Al powder particles were acquired using an automated stage with automated z‐focus; 17 size and shape parameters were measured for all particles. Approximately 37,000–2,500,000 particles/sample were analyzed using an open‐source statistical package with customized code. Dimensionality reduction was required for processing the large datasets: eight of the 17 measured variables were selected based on inspection of the correlation matrix. Data from four subsamples from each of the 56 samples produced using “in‐house” methods were analyzed using ANOVA to assess the within‐ and between‐sample variation. High within‐sample variation was noted; however, ANOVA and post‐hoc Tukey's honestly significant difference (HSD) tests demonstrated that the between‐sample variation was substantially larger than the within‐sample variation. Each sample could be differentiated from all other samples in the test set. Future experiments will focus on ways to reduce the within‐sample variation, and additional statistical and microanalytical methods to classify sources and confidently constrain the method of Al powder manufacture.     

毛细管电泳技术分析炸药残留物中无机离子

目的　建立炸药残留物中无机离子的毛细管电泳检测方法。方法　运用缓冲溶液使无机离子在毛细管电泳中达到分离 ,采用紫外间接检测法分析。结果　该方法可从爆炸残留物中准确检测出无机阴离子 (Cl- 、SO2 - 4、NO- 2 、NO- 3、ClO- 3和ClO- 4离子 )和无机阳离子 (NH 4、K 、Na 和Mg2 离子 )。结论　操作方法简便快捷 ,检材用量少 ,检测极限可达ng/ml级 ,分析结果满意     

物业管理相关问题再探析

《中华人民共和国物权法(草案)》第84条、第85条和第87条对物业管理作出了相应的规定。该草案与国务院令第379号公布的,并自2003年9月1日起施行的《物业管理条例》有所衔接,但却过于原则。鉴于《物业管理条例》实施两年多来,在物业管理权的性质、物业管理合同的归类及业主委员会的法律地位等问题上一直存有争议,人们期盼《物权法(草案)》能给予一个明确的说法。然而,就《物权法(草案)》的现行条款来看,仍然是不够明晰的,故进一步探讨物业管理的相关问题实属必要。     

Patient termination of a life-sustaining medical device: Suicide or natural death?

Medical technology has made tremendous strides in extending the lives of patients who have suffered organ failure. Machines can now replace the function of the kidneys, the heart, and other vital organs. Much has been written about a patient's right to refuse or direct the withdrawal of medical treatment, especially at the end of life, under the guise of “death with dignity.” However, little attention has been paid to the situation where a patient elects to deactivate their life-sustaining medical device without a physician's involvement. This raises the challenging question of whether the patient's manner of death should be classified as suicide or natural. Surprisingly, common law, statutes, medical ethics, and public health practice are not in alignment on the answer. This article will explore the ramifications and far-reaching impact that such divergence has on the survivors and the medical community, as well as recommend corrective actions and practical approaches for the medical and legal practitioner.     

Haptics in forensics: The possibilities and advantages in using the haptic device for reconstruction approaches in forensic science

Non-invasive documentation methods such as surface scanning and radiological imaging are gaining in importance in the forensic field. These three-dimensional technologies provide digital 3D data, which are processed and handled in the computer. However, the sense of touch gets lost using the virtual approach. The haptic device enables the use of the sense of touch to handle and feel digital 3D data. The multifunctional application of a haptic device for forensic approaches is evaluated and illustrated in three different cases: the representation of bone fractures of the lower extremities, by traffic accidents, in a non-invasive manner; the comparison of bone injuries with the presumed injury-inflicting instrument; and in a gunshot case, the identification of the gun by the muzzle imprint, and the reconstruction of the holding position of the gun.The 3D models of the bones are generated from the Computed Tomography (CT) images. The 3D models of the exterior injuries, the injury-inflicting tools and the bone injuries, where a higher resolution is necessary, are created by the optical surface scan.The haptic device is used in combination with the software FreeForm Modelling Plus™ for touching the surface of the 3D models to feel the minute injuries and the surface of tools, to reposition displaced bone parts and to compare an injury-causing instrument with an injury.The repositioning of 3D models in a reconstruction is easier, faster and more precisely executed by means of using the sense of touch and with the user-friendly movement in the 3D space. For representation purposes, the fracture lines of bones are coloured. This work demonstrates that the haptic device is a suitable and efficient application in forensic science. The haptic device offers a new way in the handling of digital data in the virtual 3D space.     

The use of orthopedic surgical devices for forensic identification

Surgically implanted devices have become increasingly common in modern skeletal material. Therefore, having the knowledge of the variety of implanted orthopedic devices, their manufacturer, and where to find and how to use identifying numbers in such implants can assist in the identification process when traditional methods are not applicable. Orthopedic device manufacturers are required by the Safe Medical Devices Act of 1990 and the FDA Modernization Act of 1997 to track permanently implanted devices. Manufacturer information on orthopedic devices associates the orthopedic surgeon who implanted the device with the patient. By providing a current list of the most common orthopedic device manufacturers in the U.S.A. and the associated contact information, investigators will have updated tools for the individuation process. Despite numerous complicating factors regarding how device data are tracked, the information presented here can assist forensic professionals with obtaining presumptive and/or positive identifications.     

Forensic acquisition and analysis of palm webOS on mobile devices

The emergence of webOS on Palm devices has created new challenges and opportunities for digital investigators. With the purchase of Palm by Hewlett Packard, there are plans to use webOS on an increasing number and variety of computer systems. These devices can store substantial amounts of information relevant to an investigation, including digital photographs, videos, call logs, SMS/MMS messages, e-mail, remnants of Web browsing and much more. Although some files can be obtained from such devices with relative ease, the majority of information of forensic interest is stored in databases on a system partition that many mobile forensic tools do not acquire. This paper provides a methodology for acquiring and examining forensic duplicates of user and system partitions from a device running webOS. The primary sources of digital evidence on these devices are covered with illustrative examples. In addition, the recovery of deleted items from various areas on webOS devices is discussed.     

Investigative studies into the recovery of DNA from improvised explosive device containers

Apprehending those who utilize improvised explosive devices (IEDs) is a national priority owing to their use both domestically and abroad. IEDs are often concealed in bags, boxes, or backpacks to prevent their detection. Given this, the goal of the research presented was to identify IED handlers through postblast DNA recovery from IED containers. Study participants were asked to use backpacks for 11 days, after which they served as containers for pipe bombs. Eleven postdeflagration backpack regions likely to be handled were swabbed and analyzed via mini-short tandem repeats (miniSTRs) and alleles were called blind. An experimental consensus method was examined in which profiles from all regions were considered, to help identify spurious drop-in/out. Results were correct for all loci, except one that remained ambiguous. The results show that recovering DNA from IED containers is a viable approach for aiding in the identification of those who may have been involved in an IED event.     

The Identification of Chlorinated Acetones in Analyses of Aged Triacetone Triperoxide (TATP)

The organic peroxide explosive triacetone triperoxide (TATP) is regularly encountered by law enforcement agents in various stages of its production, storage, or usage. In a previous study, it has been demonstrated that isolated, rigorously purified, TATP may degrade to form a series of chlorinated acetones when directly treated with excess concentrated hydrochloric acid. The current study extends this work to examine whether this phenomenon may be measured during the more feasible scenario of aging of rudimentarily purified TATP contaminated with trace reaction mixture. It was demonstrated that solid-phase microextraction gas chromatography/mass spectrometry analyses of aged TATP that was synthesized utilizing hydrochloric acid catalyst may identify the presence of the degradation products chloroacetone and 1,1-dichloroacetone. Upon aging of TATP synthesized utilizing either sulfuric or nitric acid catalyst, no acid specific degradation products could be identified. These findings may be exploited by forensic chemists in the analyses of TATP samples.     

Results of the 2018 Rapid DNA Maturity Assessment

Three commercially available integrated rapid DNA instruments were tested as a part of a rapid DNA maturity assessment in July of 2018. The assessment was conducted with sets of blinded single-source reference samples provided to participants for testing on the individual rapid platforms within their laboratories. The data were returned to the National Institute of Standards and Technology (NIST) for review and analysis. Both FBI-defined automated review (Rapid DNA Analysis) and manual review (Modified Rapid DNA Analysis) of the datasets were conducted to assess the success of genotyping the 20 Combined DNA Index System (CODIS) core STR loci and full profiles generated by the instruments. Genotype results from the multiple platforms, participating laboratories, and STR typing chemistries were combined into a single analysis. The Rapid DNA Analysis resulted in a success rate of 80% for full profiles (85% for the 20 CODIS core loci) with automated analysis. Modified Rapid DNA Analysis resulted in a success rate of 90% for both the CODIS 20 core loci and full profiles (all attempted loci per chemistry). An analysis of the peak height ratios demonstrated that 95% of all heterozygous alleles were above 59% heterozygote balance. For base-pair sizing precision, the precision was below the standard 0.5 bp deviation for both the ANDE 6C System and the RapidHIT 200.