Determination of potassium/sodium ratio in heart tissue. Evaluation of its use as an index of myocardial ischaemic damage. Comparison with the nitro-BT test

The succinate dehydrogenase method of staining and the determination of the K⁺/Na⁺ ratio of heart tissue have been applied to forensic material as a tool for demonstrating early signs of myocardial infarctions. Both methods are controlled by a series of forensic cases dying from causes other than arteriosclerosis of the coronary arteries. Based on an analysis of normal material some factors influencing the K⁺/Na⁺ ratio are defined. It is concluded that the determination of the K⁺/Na⁺ ratio shows more infarcts than the formazan method; however, the evaluation of the K⁺/Na⁺ ratio is difficult. The K⁺/Na⁺ determination is not recommended for routine use. A possible indication for the use of the K⁺/Na⁺ determination together with the formazan test could be cases of instantaneous death by accidents suspected to have been provoked by a fatal heart attack.     

A Comparison of Chemical Enhancements for the Detection of Latent Blood,,

Luminol, Bluestar^®, and Hemascein^® were tested to compare detection sensitivities to latent blood. Untreated, EDTA‐treated human blood, and a catalytically similar blood substitute were diluted (neat to 1:1,000,000) and pipetted onto a variety of substrates. Luminol and Bluestar^® performed similarly on all surfaces and fabrics. Hemascein^® yielded poor results on wood surfaces, but performed well in the detection of latent blood on fabrics. Results from untreated, EDTA‐treated, and synthetic blood results indicate that EDTA‐treated blood is similar or slightly less sensitive than untreated blood at all dilutions and on all substrates, and the synthetic blood is less sensitive than real blood, but consistent in detection threshold and thus is useful as a training aid. Additionally, some foods and household chemicals that have previously been shown to cross‐react were tested with Bluestar^®, Hemascein^®, and luminol. Hemascein^® cross‐reacted with many substances, while both luminol reagents were more discriminating.     

1,2,4‐Triazine‐Based Chromogenic Reagents for the Detection of Microtraces of Various Metals Left on Human Skin*

Abstract: This article extends the application of 1,2,4‐triazine‐based chromogenic reagents to the detection of nonferrous metal traces left on contact with canvas and human skin. The possibility of detection of iron traces resulting from contact with objects made of stainless steel was investigated as well. Additionally, the ability of triazines to form chromatic complexes with Zn²⁺, Ni²⁺, Co²⁺, Cu²⁺, Cr³⁺, and Al³⁺ ions was studied spectrophotometrically. Molar absorption coefficients, ranging from 8.8 to 29.9 × 10³/M/cm, provide high sensitivity of 1,2,4‐triazines toward nonferrous ions, thus, enabling the detection at concentrations as low as a few μM. The method was sensitive enough to detect traces resulting from a 1‐min contact with a stainless steel made object, which is commonly considered as a corrosion‐resistant material. The amounts of metal ions transferred to the skin after a 2‐min contact with objects made of brass, zinc, and copper were sufficient to develop chromatic imprints.     

A comparison of hair colour measurement by digital image analysis with reflective spectrophotometry

While reflective spectrophotometry is an established method for measuring macroscopic hair colour, it can be cumbersome to use on a large number of individuals and not all reflective spectrophotometry instruments are easily portable. This study investigates the use of digital photographs to measure hair colour and compares its use to reflective spectrophotometry. An understanding of the accuracy of colour determination by these methods is of relevance when undertaking specific investigations, such as those on the genetics of hair colour. Measurements of hair colour may also be of assistance in cases where a photograph is the only evidence of hair colour available (e.g. surveillance). Using the CIE L^*a^*b^* colour space, the hair colour of 134 individuals of European ancestry was measured by both reflective spectrophotometry and by digital image analysis (in V++). A moderate correlation was found along all three colour axes, with Pearson correlation coefficients of 0.625, 0.593 and 0.513 for L^*, a^* and b^* respectively (p-values = 0.000), with means being significantly overestimated by digital image analysis for all three colour components (by an average of 33.42, 3.38 and 8.00 for L^*, a^* and b^* respectively). When using digital image data to group individuals into clusters previously determined by reflective spectrophotometric analysis using a discriminant analysis, individuals were classified into the correct clusters 85.8% of the time when there were two clusters. The percentage of cases correctly classified decreases as the number of clusters increases. It is concluded that, although more convenient, hair colour measurement from digital images has limited use in situations requiring accurate and consistent measurements.     

Stable Isotope Ratios of Marijuana. I. Carbon and Nitrogen Stable Isotopes Describe Growth Conditions*

Abstract: There remains significant uncertainty in illicit marijuana cultivation. We analyzed the δ¹³C and δ¹⁵N of 508 domestic samples from known U.S.A. counties, 31 seized from a single location, 5 samples grown in Mexico and Colombia, and 10 northwest border seizures. For a subset, inflorescences and leaves were analyzed separately. These data revealed a strong correspondence, with inflorescences having slightly higher δ¹³C and δ¹⁵N values than leaves. A framework for interpreting these results is introduced and evaluated. Samples identified as outdoor‐grown by δ¹³C were generally recorded as such by the Drug Enforcement Administration (DEA). DEA‐classified indoor‐grown samples had the most negative δ¹³C values, consistent with indoor cultivation, although many were also in the outdoor‐grown domain. δ¹⁵N indicated a wide range of fertilizers across the dataset. Samples seized at the single location suggested multiple sources. Northwest border δ¹³C values suggested indoor growth, whereas for the Mexican and Colombian samples they indicated outdoor growth.     

Comparison of Four Saliva Detection Methods to Identify Expectorated Blood Spatter

Blood spatter analysis is an important step for crime scene reconstruction. The presence of saliva in blood spatter could indicate expectorated blood which is difficult to distinguish from impact spatter. In this study, four saliva test methods (SALIgAE^®, Phadebas^® sheet, RSID^™-Saliva kit, and starch gel diffusion) were compared to identify the best method for detecting expectorated blood spatter. The RSID^™-Saliva kit showed the highest sensitivity even when saliva was mixed with blood, and was not inhibited by the presence of blood. The SALIgAE^® test provided easy and rapid results, but the yellow color of a positive reaction was overwhelmed by the red color of the blood. The starch gel diffusion method and the Phadebas^® sheet exhibited relatively low sensitivity and the assay took a long time. When using the RSID^™-Saliva kit for identifying saliva in blood, results should be read within 10 min.     

Radiocarbon dating as tool to assist in triaging cases of unidentified human remains in Victoria,Australia: A case series

In cases where human remains are unidentified because there is no initial identification hypothesis, limited contextual information, and/or poor preservation, radiocarbon (¹⁴C) dating may be a useful tool to further assist with identification. Through measuring the amount of ¹⁴C remaining in organic material, such as bone, teeth, nail, or hair, radiocarbon dating may provide an estimated year of birth and year of death for a deceased person. This information, may assist in, establishing whether a case of unidentified human remains (UHR) is actually of medicolegal significance and therefore, requires forensic investigation and identification. This case series highlights the application of ¹⁴C dating to seven of the 132 UHR cases in Victoria, Australia. Cortical bone was sampled from each case and the level of ¹⁴C was measured to provide an estimated year of death. Four of the seven cases analyzed contained the levels of ¹⁴C consistent with an archeological timeframe, one contained a level of ¹⁴C consistent with a modern (i.e., of medicolegal significance) timeframe, and the results for the remaining two samples were inconclusive. Applying this technique not only reduced the number of UHR cases in Victoria but also has investigative, cultural, and practical implications for medicolegal casework in general.     

D5S818 Typing Discrepancy Between PowerPlex® Fusion and Other STR Kits Including GlobalFiler® Caused by a One‐base Deletion in 31 Nucleotides Upstream of the Repeat Region

Short tandem repeat (STR) typing is widely used in forensic investigation. When the same DNA sample is analyzed with different STR typing kits, a typing discrepancy is occasionally observed. In this study, we examined the cause of a typing discrepancy in a sample at D5S818 locus. This sample was designated as 10, 12 using Identifiler^®, Identifiler^® Plus, GlobalFiler^®, PowerPlex^® 16HS, and PowerPlex^® 18D, but as 9.3, 12 using PowerPlex^® Fusion. Sequencing results indicated that the shorter allele in the sample had a deletion (U31Tdel) at 31 nucleotides upstream of the repeat region (AGAT)₁₀. This deletion was located in the binding site of the published D5S818 forward primer in PowerPlex^® 16 and was only 9 and 11 nucleotides downstream of our estimated 5′ end position of D5S818 forward primer in GlobalFiler^® and PowerPlex^® 18D, respectively. We also examined the effect of primer length on the heterozygous peak balance in this sample.     

Investigating Residential History Using Stable Hydrogen and Oxygen Isotopes of Human Hair and Drinking Water

The relationship between isotopic signals in human hair and geographic region has potential forensic applications for identifying unknown individuals' place of recent residence. This study analyzes δ²H and δ¹⁸O isotopes in residential tap water and bulk hair samples from 17 volunteers representing 12 locations in Ontario, Canada. There is a strong correlation (R² = 0.9) between δ²H and δ¹⁸O values of the water samples. In contrast, the δ²H and δ¹⁸O values of the hair samples are weakly correlated (R² = 0.3), and the greater variability in the data is linked to dietary factors. This study demonstrates that the δ²H and δ¹⁸O values of hair and drinking water can be used to help identify potential place of residence in forensic cases, particularly in relation to proximity to large bodies of water such as the Great Lakes, but interpretations are complicated by the contribution of both water and diet to δ²H and δ¹⁸O values in hair.     

Investigating the Potential of Fluorescent Fingerprint Powders as a Marker for Blow Fly Larvae (Diptera: Calliphoridae)

Four fluorescent fingerprint powders (RedWop^?, GreenWop^?, Basic Yellow^?, and Yellow Powder^?) were evaluated as a marker for blow fly larvae. Administration methods included ingestion (high vs. low concentration) or topical. Ingestion of high concentrations of Basic Yellow^? and RedWop^? caused higher larval mortality. Basic Yellow^? delayed development and adult emergence while RedWop^? and Yellow Powder^? had a significant effect on particular stages of development, however, emergence time was not altered. Optimal administration is through ingestion at low concentration levels (<10%) or topically, with GreenWop^? demonstrating minimal adverse effects. Optimum wavelength for discrimination between powders was 450 nm. This research can aid in investigative training to increase visibility of larval and pupal blow flies. It can also be used in entomological studies to differentiate between larval blow flies (or other dipteran) species or individuals to further understand complex interactions and behavior during larval development.     

Fentanyl transdermal patches: Extraction and evaluation of a novel disposal method using NarcX®

Currently, there is no known commercially available product for disposing of used fentanyl transdermal patches. To eliminate the potential for harm and abuse, a proper disposal method is needed–one that neutralizes the dangerous amount of residual fentanyl that remains after therapeutic use of the fentanyl patch. The patent-pending liquid solution of activated carbon, known as NarcX^®, was investigated as a potential fentanyl adsorbing agent. In order to determine the amount of fentanyl remaining after a patch is treated with NarcX^®, here, we utilized hexanes to first dissolve the patch adhesive and then followed with liquid-liquid extraction with methanol to recover the fentanyl. Using liquid chromatography coupled to tandem mass spectrometry (LC/MS-MS), the extracts obtained with this method yielded between 85% and 117% recovery of fentanyl from new and unused patches. Further optimization of this method allowed for a quantitative evaluation of NarcX^®-treated fentanyl patches. 100 µg/h Apotex brand fentanyl patches were exposed to NarcX^® for 1, 24, 48, and 72 h. NarcX^® was shown to adsorb fentanyl from the patches with varying degrees of success, demonstrating an average of 66.98 ± 0.75% fentanyl adsorption after 72 h. These findings suggest that more work is needed to successfully neutralize the fentanyl patches in their entirety using NarcX^®; however, this work does demonstrate proof of concept.     

Carbon and Nitrogen Stable Isotope Analyses of Ephedra Plant and Ephedrine Samples and Their Application For Methamphetamine Profiling

In this study, stable isotope ratio analysis was used to track the precursor information of methamphetamine. The δ¹³C and δ¹⁵N values of 30 nature ephedra plants, 12 synthetic ephedrine/pseudoephedrine (ephedrine), 14 natural ephedrine, and 987 seized methamphetamine samples were measured and compared. Due to different weather and earth conditions, the δ¹³C and δ¹⁵N values of ephedra plants grown in the east and the west of Inner Mongolia showed great difference. The δ¹⁵N values of ephedra plants were consistent with related ephedrine extracted from them. Moreover, the criteria to infer the synthetic origin of ephedrine were set up after the analysis of natural and synthetic ephedrine samples. Finally, the precursor origins of 949 seized methamphetamine samples synthesized by Emde and Nagai method were tentatively inferred. Influenced by different preprecursors, the δ¹³C values of seized methamphetamine samples that synthesized from P2P also showed great difference, and this result is consistent with the reported data.     

Discrimination of Geographical Origin of Asian Garlic Using Isotopic and Chemical Datasets under Stepwise Principal Component Analysis

Isotopic compositions of δ²H, δ¹⁸O, δ¹³C, and δ¹⁵N and concentrations of 22 trace elements from garlic samples were analyzed and processed with stepwise principal component analysis (PCA) to discriminate garlic's country of origin among Asian regions including South Korea, Vietnam, Taiwan, and China. Results indicate that there is no single trace‐element concentration or isotopic composition that can accomplish the study's purpose and the stepwise PCA approach proposed does allow for discrimination between countries on a regional basis. Sequentially, Step‐1 PCA distinguishes garlic's country of origin among Taiwanese, South Korean, and Vietnamese samples; Step‐2 PCA discriminates Chinese garlic from South Korean garlic; and Step‐3 and Step‐4 PCA, Chinese garlic from Vietnamese garlic. In model tests, countries of origin of all audit samples were correctly discriminated by stepwise PCA. Consequently, this study demonstrates that stepwise PCA as applied is a simple and effective approach to discriminating country of origin among Asian garlics.     

A City‐wide Investigation of the Isotopic Distribution and Source of Tap Waters for Forensic Human Geolocation Ground‐truthing

Human geolocation is prefaced on the accuracy of the geographic precision of mapped isotopic values for drinking water. As most people live in cities, it becomes important to understand city water supplies and how the isotopic values uniquely reflect that city. This study investigated the isotopic distribution of δ²H and δ¹⁸O from sourced tap waters that were collected from across the Metro Vancouver (MV) area (n = 135). The results revealed that the isotopic values reflect their water sources with a range of 5.3‰ for δ¹⁸O_tap and 29.3‰ for δ²H_tap for MV. The results indicate that individual cities need higher resolution studies to determine their tap water isotopic ranges, and a good understanding of the water supply network itself for human geolocation work. With an extended high‐resolution understanding of each city, human tissue may be compared with more certainty for geolocation.     

Extraction and isolation of cannabinoids from marijuana seizures and characterization by 1H NMR allied to chemometric tools

Marijuana, a drug derived from the Cannabis sativa L. plant, is the world's most consumed illicit drug. In this paper, a total of 156 marijuana samples seized in the state of Espírito Santo (ES), Brazil were studied and analysed by proton nuclear magnetic resonance (¹H NMR) spectroscopy to identify the major cannabinoids present. A crude extract of all samples was purified using high performance liquid chromatography so that these compounds could serve as reference substances. Nine fractions were obtained and analysed by ¹H NMR and gas chromatography–mass spectrometry (GC–MS), with five presented cannabinoids. ?⁹-THC (Δ⁹-trans-tetrahydrocannabinol), ?⁹-THCA (?⁹-tetrahydrocannabinolic acid), ?⁸-THC (?⁸-tetrahydrocannabinol), 11-hydroxycannabinol, CBV (cannabivarin), and CBN (cannabinol) were found, and their chemical structures were confirmed by GC–MS. The latter compound was obtained with high purity (≈100%), while the others were obtained as less complex mixtures with purity higher than 75% (except for Δ⁸-THC). Principal component analysis (PCA) was used on the ¹H NMR spectra of the 156 samples, and it was found that the samples were grouped according to the months, differentiating into two groups (from July 2014 to January 2015 and from February 2015 to July 2015), where non-grouping was observed from four macro-regions of the ES state (North, Central, Metropolitan, and South). The chemical profile of the seized samples was correlated to the ¹H NMR spectrum of an isolated CBN sub-fraction, in which the group formed by samples seized in the year 2015 presented lower CBN content in the chemical composition. From the PCA score plot, two groups of samples were confirmed using the partial least squares discriminant analysis and orthogonal projections to latent structures classification methods.     

Particle Analysis for the Detection of Gunshot Residue (GSR) in Nasal Samples Using Scanning Laser Ablation and Inductively Coupled Plasma-Mass Spectrometry (SLA-ICPMS)

Currently, aluminum stub with carbon adhesive devices are used to collect inorganic gunshot residues (GSR) from the hands of a shooter. In an ideal shooting case, the gunshot particles do not persist for more than 2 h in the hands of the shooter, provided that the hands have not been washed. However, for forensic analysis and inference, the extended persistence of GSR would be desirable. This study investigates a novel GSR sampling and detection protocol. Sampling was performed in the nostrils using swab devices impregnated in ethylenediaminetetraacetic acid (EDTA). The GSRs persisted for longer periods in nasal mucus than on the hands, and particles were detected 6 h after shooting occurred. The analytical determination was conducted by scanning laser ablation-inductively coupled plasma-mass spectrometry (SLA-ICPMS) which enable the identification of the number of particles and their elemental composition. Seventeen isotope signals corresponding to ¹³C, ²⁰⁵Tl and 15 analytes that are usually associated with the composition of GSR residues were monitored: ²⁷Al, ²⁹Si, ³¹P, ³³S, ³⁵Cl, ³⁹K, ⁴⁴Ca, ⁵⁷Fe, ⁶⁰Ni, ⁶³Cu, ⁶⁶Zn, ¹¹⁸Sn, ¹²¹Sb, ¹³⁷Ba, and ²⁰⁸Pb. The SLA technique enabled the reduction of the swab analysis time to 40 min. The effectiveness of this methodology was evaluated with two types of firearms: a pistol and a shotgun. The results indicated that the methodology proposed for the analysis of the nasal GSR was effective and that it can improve or complement the forensic analyses and inferences presented in a court.     

The NucleoSpin DNA Clean-up XS kit for the concentration and purification of genomic DNA extracts: An alternative to microdialysis filtration

Traditionally, DNA extracts from biological evidence items have been concentrated and rinsed using microdialysis filtration units, including the Centricon^® and Microcon^® centrifugal filter devices. As an alternative to microdialysis filtration, we present an optimized method for using NucleoSpin^® XS silica columns to concentrate and clean-up aqueous extracts from the organic extraction of DNA from biological samples. The method can be used with standard organic extraction and dithiothreitol (DTT)-based differential extraction methods with no modifications to these methods prior to the concentration and clean-up step. Extracts from laboratory-prepared bloodstains, saliva and semen stains have been successfully amplified with both qPCR and STR assays. Finally, the total time to process a set of samples with the NucleoSpin^® XS column is approximately 30 min vs. approximately 1.5 h with the Centricon^® YM-100 filter device.     

Data protection: The future of privacy

The Art. 29 Working Party (hereinafter “Art. 29 WP”) is an influential body comprised of representatives from the Member State Data Protection Authorities² established under the Data Protection Directive 95/46/EC, has recently issued an opinion with the Working Party on Police and Justice. This is quite significant, since the opinion sets out some of the issues that will need to be addressed in the lead up to the revision of the Data Protection Directive 95/46/EC.³ This comes at a time, when there have been discussions on the current application of the European Data Protection Directive to the internet,⁴ (such as social networking) and the recent European Commission’s consultation on the legal framework for the fundamental right to protection of personal data. Not least, there have been a number of cases brought before the European Court of Justice dealing with the partial implementation of the Data Protection Directive 95/46/EC.⁵The aim of this paper is to consider in detail the issues set out by the Art. 29 WP and the likely challenges in revising the Data Protection Directive 95/46/EC.     

Voltammetric determination of cocaine in confiscated samples using a cobalt hexacyanoferrate film-modified electrode

In this work, a fast, non destructive voltammetric method for cocaine detection in acetonitrile medium using a platinum disk electrode chemically modified with cobalt-hexacyanoferrate (CoHCFe) film is described. The deposition of CoHCFe film at platinum disk (working electrode) was carried out in aqueous solution containing NaClO₄ at 0.1 mol L⁻¹ as supporting electrolite. Stability studies of the film and subsequent voltammetric analysis of cocaine were made in acetonitrile medium with NaClO₄ at 0.1 mol L⁻¹ as supporting electrolite. A reversible interaction between cocaine and CoHCFe at the film produces a proportional decrease of original peak current, due to the formation of a complex between cocaine and cobalt íons, with subsequent partial passivation of the film surface, being the intensity of current decrease used as analytical signal for cocaine. A linear dependence of cocaine detection was carried out in the range from 2.4 × 10⁻⁴ to 1.5 × 10⁻³ mol L⁻¹, with a linear correlation coefficient of 0.994 and a detection limit of 1.4 × 10⁻⁴ mol L⁻¹. The analysis of confiscated samples by the proposed method indicated cocaine levels from 37% to 95% (m/m) and these results were validated by comparison to HPLC technique, being obtained good correlation between both methods.     

Refining Stable Oxygen and Hydrogen Isoscapes for the Identification of Human Remains in Mississippi,

Isoscape refinement is an essential component for accurately predicting region‐of‐origin in forensic investigations involving isotope analysis of unidentified human remains. Stable oxygen (δ¹⁸O) and hydrogen (δ²H) isotopes were measured from 57 tap water samples collected across Mississippi to model refined isoscapes for the state. A tap water conversion equation, δ¹⁸O_tw=1.64 δ¹⁸Op?31.35, was developed for the southeastern USA to test the prediction accuracy of the δ¹⁸O_tw isoscape using individuals with known residential histories. A local Mississippi resident (USAFA‐134) was assigned with 90% probability to the correct region‐of‐origin reported by the participant. Assignments for Georgia residents (USAFA‐118 and USAFA‐205) had variable results, predicting USAFA‐118 from Mississippi and USAFA‐205 as a nonlocal resident. Stable isotope values often overlap geographically and a multi‐isotope approach should be used when narrowing region(s)‐of‐origin(s). This study demonstrates the utility of refining isoscapes and the importance of tissue calibration in prediction assignments of human remains.