The outcome of the forensic triage preceding disaster victim identification in the downing of Malaysia Airlines flight 17.

Malaysia Airlines flight 17 crashed on 17 July 2014 while flying over an area of armed conflict in eastern Ukraine. The first forensic trace evidence was collected after the human remains were transferred to a safe location in the Netherlands for identification and repatriation. Disaster victim identification processes were therefore undertaken in concert with the forensic investigation. Prior to these processes, X-ray and computed tomography scanners were used to reveal foreign objects in the human remains, and a large number of these fragments were recovered after the forensic triage. A distinct group of metal fragments was identified as being potential remnants of high-energy foreign objects. Forensic analysis revealed that they were explosively deformed unalloyed steel fragments, some of which had shapes consistent with pre-formed metal fragments found in a 9N314M warhead used in Buk SA-11 missiles. Furthermore, thin film deposits of cockpit glass and aluminium were identified on the most heavily deformed side of some of the explosively deformed metal fragments, suggesting they came from outside the airplane. These findings supported early suspicions that Malaysia Airlines flight 17 was struck by a Buk SA-11 missile. KeypointsA multidisciplinary approach for combined identification and forensic investigation of human remains after a mass fatality incident.The combined use of complementary X-ray techniques for detection and provisional characterization of foreign objects in human remains.The use of sensitive and highly discriminative state of the art techniques for analysing foreign objects recovered from human remains.

Determination of seventeen major and trace elements in new float glass standards for use in forensic comparisons using laser ablation inductively coupled plasma mass spectrometry.

Consensus concentration values for seventeen (17) major and trace elements typically present in soda-lime glass manufactured using the "float " process and used in the quantitative analysis and forensic comparison of glass samples were determined using laser ablation (LA) micro sampling coupled to inductively coupled plasma mass spectrometry (ICP-MS). This is the first reporting of the chemical characterization of a new set of float glass intended for use as matrix-matched calibration standards in the forensic analysis and comparison of glass by LA-ICP-MS using a standard test method (ASTM E2927-16e1). Three Corning Float Glass Standards (CFGS) were manufactured at low, medium, and high concentrations of 32 elements typically encountered in float glass samples as found in forensic casework. This work describes an international collaboration among seven (7) laboratories to evaluate the homogeneity of the three glass materials and reports the consensus concentrations values of 17 elements at three concentration levels. Eight (8) sets of independent results from LA-ICP-MS analysis using the standard test method of analysis and one set of micro-X-ray Fluorescence Spectrometry (µXRF) data (using method ASTM E2926-17) resulted in typically <3% relative standard deviation (RSD) within each lab and < 5% RSDs among all labs participating in the study for the concentration ranges using sampling spots between 50 µm - 100 µm in diameter. These results suggest that the new calibration standards are homogeneous for most elements at the small sampling volumes (~ 90 µm deep by ~80 µm in diameter) reported and show excellent agreement among the different participating labs. Consensus concentration values are determined using a previously reported calibration standard (FGS 2) and checked with a NIST 1831 SRM®. A collaboration with National Institute of Standards and Technology (NIST) scientists to certify these glasses as SRMs, including the certification of the quantitative analysis of the minor and trace element content, for future distribution by NIST is ongoing.

Virtual and simulated striated toolmarks for forensic applications.

Large numbers of experimental toolmarks of screwdrivers are often required in casework of toolmark examiners and in research environments alike, to be able to recover the angle of attack of a crime scene mark and to determine statistically meaningful properties of toolmarks respectively. However, in practice the number of marks is limited by the time needed to create them. In this article, we present an approach to predict how a striated mark of a particular tool would look like, using 3D surface datasets of screwdrivers. We compare these virtual toolmarks qualitatively and quantitatively with real experimental marks in wax and show that they are very similar. In addition we study toolmark similarity, dependent on the angle of attack, with a very high angular resolution of 1°. The results show that for the tested type of screwdriver, our toolmark comparison framework yields known match similarity scores that are above the mean known non-match similarity scores, even for known match differences in angle of attack of up to 40°. In addition we demonstrate an approach to automatically recover the angle of attack of an experimental toolmark and experiments yield high accuracy and precision of 0.618 ± 4.179°. Furthermore, we present a strategy to study the structural elements of striated toolmarks using wavelet analysis, and show how to use the results to simulate realistic toolmarks.

Toolmark variability and quality depending on the fundamental parameters: Angle of attack, toolmark depth and substrate material.

The traditional way of visual toolmark comparison includes subjective judgments. Automated methods using computers are a possibility to render a comparison more objective, but they require the statistical properties, like the similarity and variability, of toolmarks to be determined quantitatively. Several parameters, that play a role during toolmark creation, are statistically analyzed in this article. We determined the same toolmark and the different toolmark similarity as well as variability of known matching toolmarks created in wax and compared the results with the similarity and variability of known non-matching toolmarks. In addition we studied the influence of the substrate materials wax and lead and the angle of attack on toolmark similarity and variability. Furthermore, we present an approach to determine toolmark quality, defined as how well structural details are preserved in the toolmark, to assist toolmark examiners in deciding, which structural details are reliable in a mark. We studied the influence of the substrate material, the angle of attack and the depth of a toolmark on the quality. The results show that for known matching toolmarks, the variability is very low within a toolmark and between toolmarks in wax, given that the parameters angle of attack and depth are held constant. Geometrical details are reliably represented down to 10-50µm and toolmark similarity is clearly higher than known non-matching similarities. The comparison of wax and lead shows that wax is a good alternative as a substrate material for experimental toolmarks, capable of reliably representing structural details down to 10-25µm. For finer details, lead is a better choice but might alter the original state of a tool. With increasing angle of attack, toolmark variability increases and toolmark quality decreases. Therefore it is advantageous to push the tool instead of pulling during toolmark creation for angles of attack above ≈45°. The quality also decreases with increasing toolmark depth, but only up to ≈300µm. Therefore toolmarks should be created as shallow as possible in the substrate material.

Microscopic residues of bone from dissolving human remains in acids.

Dissolving bodies is a current method of disposing of human remains and has been practiced throughout the years. During the last decade in the Netherlands, two cases have emerged in which human remains were treated with acid. In the first case, the remains of a cremated body were treated with hydrofluoric acid. In the second case, two complete bodies were dissolved in a mixture of hydrochloric and sulfuric acid. In both cases, a great variety of evidence was collected at the scene of crime, part of which was embedded in resin, polished, and investigated using SEM/EDX. Apart from macroscopic findings like residual bone and artificial teeth, in both cases, distinct microscopic residues of bone were found as follows: (partly) digested bone, thin-walled structures, and recrystallized calcium phosphate. Although some may believe it is possible to dissolve a body in acid completely, at least some of these microscopic residues will always be found.

Quantitative comparison of striated toolmarks.

A comparison of striated toolmarks by human examiners is dependent on the experience of the expert and includes a subjective judgment within the process. In this article an automated method is presented for objective comparison of striated marks of screwdrivers. The combination of multi-scale registration (alignment) of toolmarks, that accounts for shift and scaling, with global cross correlation as objective toolmark similarity metric renders the approach robust with respect to large differences in angle of attack and moderate toolmark compression. In addition, a strategy to distinguish between relevant and non-relevant spatial frequency ranges (geometric details) is presented. The performance of the method is evaluated using 3D topography scans of experimental toolmarks of 50 unused screwdrivers. Known match and known non-match similarity distributions are estimated including a large range of angles of attack (15, 30, 45, 60 and 75°) for the known matches. It is demonstrated that the system has high discriminatory power, even if the toolmarks are made at a difference in angle of attack of larger than 15°. The probability distributions are subsequently employed to determine likelihood ratios. A comparison of the results of the automated method with the outcome of a toolmark comparison experiment involving three experienced toolmark examiners reveals, that the automated system is more powerful in correctly supporting the hypothesis of common origin for toolmarks with a large difference in angle of attack (30°). In return, the rate of toolmark comparisons that yield incorrect support for the hypothesis of common origin is higher for the automated system. In addition, a comparison between estimating known match and known non-match distributions using 2D and 3D data is presented and it is shown that for toolmarks of unused screwdrivers, relying on 3D is slightly better than relying on 2D data. Finally, a comparison between estimating known match and known non-match distributions for two different types of screwdrivers suggests, that the method may be used for comparing marks of other tools as well.

Fast photo-processes in triazole-based push-pull systems.

Electron donor-acceptor compounds 1 (asymmetrical push-pull derivative) and 2 (symmetrical push-pull-push derivative) were studied in which one (push-pull) or two aniline units (push-pull-push) are connected to a biphenyl group via triazole linkers, made by "click" chemistry. Steady-state and time-resolved spectroscopies indicate that highly dipolar charge separated excited states are populated in moderately polar solvents. The very similar photophysical behavior of both compounds implies symmetry breaking in the excited state of 2. The polarity of the solvent determines the efficiency of formation of the charge separated state. While in toluene it is very low, it becomes very high in acetonitrile. The bis-triazole substituted biphenyl unit in 2 behaves as a better electron acceptor than the mono-triazole substituted biphenyl in 1, which leads to a more facile charge separation in 2. Rates of charge separation are of the order of 10(11)-10(12) s(-1), and increase with solvent polarity.

A push-pull aromatic chromophore with a touch of merocyanine.

The solvatochromic behavior of N-(2,5-di-tert-butylphenyl)-9-pyrrolidinoperylene-3,4-dicarboximide () was investigated by measuring the excitation and emission spectra over a wide range of temperature in 2-methyltetrahydrofuran (MTHF). The temperature induced spectral changes can be compared with the changes caused by changing solvent polarity using different solvents at room temperature. In both cases a strong positive solvatochromism is observed both in absorption/excitation and in emission. The difference between excitation and emission energies decreases with increasing solvent polarity. The behavior of can be rationalized in terms of a change in electronic structure with solvent polarity. Although has the typical molecular structure of a push-pull substituted aromatic system, in which the solvatochromic shift in emission is normally larger than that in absorption, in its solvent-induced electronic structure change it resembles a merocyanine.

Paradoxical solvent effects on the absorption and emission spectra of amino-substituted perylene monoimides.

In N-(2,5-di-tert-butylphenyl)-9-pyrrolidinoperylene-3,4-dicarboximide (5PI) the absorption and emission spectra display large solvatochromic shifts, but, remarkably, the Stokes shift is practically independent of solvent polarity. This unique behavior is caused by the extraordinarily large ground-state dipole moment of 5PI, which further increases upon increasing the solvent polarity, whereas the excited-state dipole moment is less solvent dependent. In the corresponding piperidine compound, 6PI, this effect is much less important owing to the weaker coupling between the amino group and the aromatic imide moiety, and in the corresponding naphthalimide, 5NI, it is absent. The latter shows the conventional solvatochromic behavior of a push-pull substituted conjugated system, that is, minor shifts in absorption and a larger change in the emission energy with solvent polarity.

Solitary splenic metastasis in a patient with a malignant melanoma diagnosed with F-18-FDG PET scanning.

A 71-year-old woman with a history of stage III melanoma was hospitalized for evaluating fever of unknown origin and severe left upper quadrant abdominal pain. A computed tomography scan of the abdomen revealed a solitary lesion in the spleen, 10.5 x 10.4 x 10.1-cm, causing splenomegaly. Fused F-18 FDG PET/CT images revealed a solitary splenic metastasis and a focus of increased uptake in the region of the previously removed melanoma at the right scapula. Based on the clinical findings and CT and PET scans, malignant melanoma (stage IV) was diagnosed. Splenectomy was performed subsequently. The histopathologic finding was consistent with a metastasis of a melanoma.