A novel method for the analysis of discharged smokeless powder residues

A novel method for the estimation of intermediate-long firing distance range is proposed. The method is based on the characterization and chemical analysis of the smokeless powder particles on the target. An adhesive lifter is applied to collect the suspected gunshot residues (GSRs) from the surface of an object, and a Modified Griess Test (MGT) is carried out after alkaline hydrolysis on the adhesive lifter. Visualized particles are removed from the adhesive lifter under a microscope. Two systems are used for the analysis of organic discharge residues from the smokeless powder: (1) gas chromatography/thermal energy analysis (GC/TEA) for the analysis of nitroglycerine (NG) and 2,4-dinitrotoluene (2,4-DNT), (2) gas chromatography/mass spectrometry (GC/MS) for the identification of organic components such as DNT, NG, and some stabilizers. By using this procedure and confirming that the suspected particles are indeed GSR, one can estimate the intermediate-long firing distance of c. 0.75-3 m in the presence of very few particles and provide information for the classification of ammunition type in casework.     

A GC/MS study of the drying of ballpoint pen ink on paper

The determination of the age of an ink entry from a questioned document is often an essential problem and a controversial issue in forensic sciences. Therefore, it is important to understand the aging process of the different components found in ink. The aim of this work was to study the drying process of ballpoint ink, characterised by the disappearance of volatile solvents from the ink entry. Phenoxyethanol is of particularly high interest as it is found in more than 80% of the blue ballpoint pens at different concentrations. Liquid extraction followed by splitless gas chromatography/mass spectrometry in the selected ion mode was used to measure the quantitative decrease of solvents from ink entries made with a blue Parker ballpoint pen. Quantities of ethoxyethoxyethanol, dipropylene glycol, phenoxyethanol and phenoxyethoxyethanol were studied in ink entries up to 1.5 years old, thus allowing to calculate aging curves for this particular pen. The low quantities of solvents (in the microgram range for a 1 cm ballpoint entry) were found to decrease quickly after deposition of the ink on paper through the competitive processes of evaporation and diffusion. Losses of up to 75% of solvents were observed after a few seconds. The amount of ethoxyethanol stopped decreasing after about 10 days (quantities reached the nanogram range for a 1 cm ballpoint entry), while the aging curves of dipropylene glycol, phenoxyethanol and phenoxyethoxyethanol level off considerably after 2 weeks. It was observed that ethoxyethanol, dipropylene glycol and phenoxyethanol can also migrate from one sheet of paper to another if placed close enough (e.g. in a book or a stack of papers), therefore contamination from fresh ink strokes from other paper sheets has to be taken into account for those solvents. In this paper we demonstrate that differentiation between fresh ink (<2 weeks) and older inks is possible under laboratory storage conditions. For real cases samples, more parameters have to be studied and other possible pathways have to be considered.     

Origin assignment of unidentified corpses by use of stable isotope ratios of light (bio-) and heavy (geo-) elements--a case report

An unknown male body was found near an expressway in Germany. As different criminalistic and forensic methods (e.g. tooth status, fingerprint or DNA-analysis) could not help to identify the person, multielement stable isotope investigations were applied. The combined analysis of stable isotope ratios of light (H, C, N) and heavy elements (Pb, Sr) on the man's body tissues supported to assign him to Romania. The case report demonstrates an application of multielement-isotope analysis in the forensic fields and its potential.     

Allelic and haplotypic frequencies at 11 Y-STR loci in Buryats from South-East Siberia

We have obtained Y-STR haplotypes in 12 loci (DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439) from 215 Buryat males. We have found that one haplotype (15-11,18-13-28-23-10-11-14-14-10-12) comprises more than 30% of Y chromosomes in this population while another haplotype (14-11,13-14-30-23-10-14-14-14-10-10) comprises additional 14% of chromosomes. The population under study seems to be very homogenous as far as Y chromosome is regarded and the most frequent haplotype seems to be the modal haplotype for Buryats.     

The Court of Public Opinion: Lay Perceptions of Polygraph Testing

We sampled a total of 411 participants and randomly assigned them one of three brief trial vignettes that contained either no-polygraph evidence, evidence of a passed polygraph test, or evidence of a failed polygraph test. Participants rendered guilt judgments and answered a series of questions concerning the trial in particular, and polygraph tests in general. Similar to previous studies on the impact of polygraph evidence on jurors' guilt judgments, this sample of jury-eligible adults indicated that they did not find polygraph test evidence to be persuasive. Moreover, it mattered little to participants whether the results indicated the defendant passed a polygraph test, or that he failed a polygraph test. However, when our findings are compared to those of previous surveys involving experts in the field of psychophysiology, they differ in a number of important respects. The implications for decisions regarding admissibility (e.g., U.S. v. Alexander, 1975 and U.S. v. Scheffer, 1998) are discussed.     

Influence of blood loss on the pharmacokinetics of citalopram

Extended blood loss results in several compensatory physiological mechanisms, including transfer of extravascular fluid into the blood circulation. If drugs are present in the body, this fluid exchange may imply that blood drug concentrations found in a trauma victim may differ from the concentrations present at the time of the trauma. To address this issue, an animal model was used to investigate the influence of blood loss on pre-existing levels of the antidepressant drug citalopram and its demethylated metabolites. Rats were administered citalopram either acutely (40 mg/kg, orally) or chronically (20 mg/kg daily, subcutaneously) for 6 days using osmotic pumps. In the experimental rats, blood loss was accomplished by withdrawing 0.8 mL blood at 10 min intervals during 70 min. In the control rats, blood was withdrawn at 0 and 70 min only. Blood, brain and lung drug concentrations were analyzed with an enantioselective HPLC method. In the chronically treated rats, the ratios between final and initial citalopram concentrations were 1.08 +/- 0.15 and 1.01 +/- 0.09 in the experimental rats and controls, respectively, indicating no major effect of blood loss. In contrast, acute oral administration resulted in increased ratios in the exsanguinated rats as compared to controls (1.84 +/- 0.50 versus 0.73 +/- 0.07; p = 0.0495). In conclusion, the observation of increased blood drug levels in the acute oral rats indicates that absorption of fluid from the gastrointestinal tract may be important in the intravascular refill. Further, in the interpretation of post-mortem blood levels of drugs, these physiological mechanisms should be taken into account.     

Cyanide quantification in post-mortem biological matrices by headspace GC-MS

Cyanide is a powerful chemical asphyxiant found in some forensic cases following voluntary (suicide) or involuntary ingestion (fire, accidental exposure). A quantification method for cyanide that is specifically suited to post-mortem forensic purposes was developed. Determination was performed by headspace gas chromatography coupled to mass spectrometry using a GS-GASPRO column on an HP-6890 gas chromatograph with an HP-5973N mass detector. The biological sample was treated with an internal standard, frozen, glacial acetic acid was added and the sample was then incubated at 60°C for 15min. The headspace was sampled with a disposable syringe, and analyzed to quantify hydrogen cyanide. Isotopically labeled cyanide ((13)C(15)N) was used as the internal standard to minimize matrix effect and sampling error. The method produced an extended linear dynamic range (0.07-50μg/mL), and a method detection limit of 0.02μg/mL. Identical calibration curves were obtained when blood, gastric contents and aqueous solutions were used as the calibration standard matrix. This method was also successful in quantitating cyanide in gastric contents, one of the most variable biological fluids. The method has been validated and is being used for current forensic cases such as fire victims and suicides.     

Industry-sponsored medical education--in the quest for professional integrity and legal certainty

Industry-sponsored medical education is a much disputed issue. So far, there has been no regulatory framework which provides clear and definite rules as to whether and under what circumstances the sponsorship of medical education is acceptable. State regulation does not exist, or confines itself to a very general principle. Professional regulation, even though applied frequently, is rather vague and indefinite, raising the general question as to whether self-regulation is the right approach at all. Certainly, self-regulation by industry cannot and should not replace other regulatory approaches. Ultimately, advertising law in general and the European Directive 2001/83/EC specifically, might be a good starting point in providing legal certainty and ensuring the independence of medical education. Swiss advertising law illustrates how the principles of the European Directive could be implemented clearly and unambiguously.