Analysis of Mitochondrial DNA from a Burned,Ninhydrin‐Treated Paper Towel

Contact‐based evidence is likely to have limited quantities of DNA and may yield mixed profiles due to preexisting or contaminating DNA. In a recent arson investigation, a paper towel was collected and used as circumstantial evidence. The paper towel was partially burned and was likely set on fire with flammable liquid. As part of the investigation, the paper towel was treated with ninhydrin to visualize fingerprint evidence. Initial DNA analysis of two swabs was negative for short tandem repeat (STR) markers and revealed a mixture of mitochondrial DNA (mtDNA). Analysis of 13 additional cuttings yielded four more mixed profiles, but also two samples with a common single‐source profile. The single‐source mtDNA profile matched that of the primary suspect in the case. Thus, even if initial mtDNA analysis yields a mixed profile, a sampling strategy involving multiple locations can improve the chance of obtaining valuable single‐source mtDNA profiles from compromised evidence in criminal casework.     

The Politics of Fertility and Economic Development

This paper presents a formal model that characterizes the two faces of development—persistent poverty, and industrialization and rising incomes—and establishes that the interaction between politics and economics determines which path a nation travels. We demonstrate that political factors affect fertility decisions so that a one-time disturbance compounds across generations, impacting a country's entire development trajectory. Modeling strategic multiobjective policy-setting by the government, we derive a new concept of political capacity and prove that a sufficient amount of political capacity is necessary to escape a poverty trap and develop the economy. Empirical tests for a sample of 100 countries from 1960 to 1990 provide strong support for the predictions of the formal model. In particular, we show that both political stability and political capacity significantly influence birth rates. We conclude that politics can be either a stimulant or a barrier to economic development.     

Ideological Congruence and Electoral Institutions

Although the literature examining the relationship between ideological congruence and electoral rules is quite large, relatively little attention has been paid to how congruence should be conceptualized. As we demonstrate, empirical results regarding ideological congruence can depend on exactly how scholars conceptualize and measure it. In addition to clarifying various aspects of how scholars currently conceptualize congruence, we introduce a new conceptualization and measure of congruence that captures a long tradition in democratic theory emphasizing the ideal of having a legislature that accurately reflects the preferences of the citizenry as a whole. Our new measure is the direct counterpart for congruence of the vote-seat disproportionality measures so heavily used in comparative studies of representation. Using particularly appropriate data from the  Comparative Study of Electoral Systems,  we find that governments in proportional democracies are not substantively more congruent than those in majoritarian democracies. Proportional democracies are, however, characterized by more representative legislatures.     

Analysis of friction ridge evidence for trace amounts of paracetamol in various pharmaceutical industries by Raman spectroscopy

The detection of potentially harmful substances presents a multifaceted challenge. On one hand, it can directly save lives, on the other, it can significantly aid and enhance police work, thereby increasing the effectiveness of investigations. The research conducted in this study primarily aims to identify paracetamol in fingerprints, considering situations involving direct contact of a person with paracetamol either chronically or in a single dose. The identification procedure presented, utilizing Raman spectroscopy, aims to rapidly detect the xenobiotic following ingestion by an individual, which involves touching the tablet with their fingers—this can be termed as touch evidence in forensic science investigations. Additionally, the authors focus on assessing the impact of additives present in drugs containing paracetamol as the main active ingredient. The screening results obtained will enable us to analyze the composition of drugs in terms of potentially toxic substances, and their influence on the physicochemical activity of the active substance. We successfully identified the paracetamol molecule using a noninvasive forensic trace detection method. Samples in the form of common drugs containing 500 mg of paracetamol were studied. Throughout the study, comprehensive validation of the method was ensured through the utilization of a statistical model, which excluded sensitivity to the presence of other substances, whether additives or from the external environment. The proposed approach to trace the content of substances in fingerprint using Raman scattering analysis provides a useful starting point to enhance current analytical methods not only in forensic science but also in toxicology.     

Application of capillary electrophoresis to examination of color inkjet printing inks for forensic purposes

In the process of questioned document examination, the discrimination of inkjet printing inks is becoming more necessary due to increasingly frequent counterfeiting of documents printed by inkjet printers. Therefore, a method based on micellar electrophoretic capillary chromatography (MECC) has been developed and applied to analysis of such inks extracted from paper. With the use of an optimized and validated analytical procedure, multielectropherograms of inks taken from various models of printers made by various producers (Hewlett-Packard, Epson, Brother, Lexmark and Canon) were created. It was shown that effective differentiation of individual inks was possible in terms of migration time, order and specific shapes of characteristic peaks. By comparison of recorded UV-Vis spectra, the identification of main dyes was also achievable. The usefulness of the method was confirmed by an intralaboratory test of utility, in which several forged printouts were successfully examined. The obtained results proved that the proposed procedure is a useful tool that could be applied to ink discrimination and group identification of dyes originating from inkjet printing inks. Consequently, the developed method can be applied in the forensic field, including investigation of the authenticity of documents.