An STR Melt Curve Genotyping Assay for Forensic Analysis Employing an Intercalating Dye Probe FRET*

Abstract: The most common markers used in forensic genetics are short tandem repeats (STRs), the alleles of which are separated and analyzed by length using capillary electrophoresis (CE). In this work, proof of concept of a unique STR genotyping approach has been demonstrated using asymmetric PCR and a fluorescence resonance energy transfer (FRET)‐based hybridization analysis that combines fluorophore‐labeled allele‐specific probes and a DNA intercalating dye (dpFRET) in a melt match/mismatch analysis format. The system was successfully tested against both a simple (TPOX) and a complex (D3S1358) loci, demonstrated a preliminary detection limit of <10 genomic equivalents with no allelic dropout and mixture identification in both laboratory‐generated and clinical samples. With additional development, this approach has the potential to contribute to advancing the use of STR loci for forensic applications and related fields.     

Effects of histological staining on the analysis of human DNA from archived slides

Abstract: Archived slides of cell smears treated with histological stains for sperm detection are often the only source of DNA available when cold cases are reopened. There have been conflicting reports as to the negative effects of particular histological stains on DNA recovery and quality from human cells, making stain selection an important consideration for forensic laboratories. This study investigates the effect of several staining systems on DNA recovery from histological slide samples stored from 0 to 10 weeks. DNA profiles obtained after analysis of these samples with AmpFlSTR^® Identifiler? and increased cycle AmpFlSTR^® SGM Plus? short tandem repeat (STR) profiling systems and the effects that these stains have on DNA quantity and quality over time are described. Results indicate that Christmas Tree and Hematoxylin and Eosin stains do not have significantly different effects on DNA quality after 10‐week storage of slides. This research will assist scientists to select staining systems that have minimal deleterious effects on the DNA recovered.     

Relationships among alcohol outlet density, alcohol use, and intimate partner violence victimization among young women in the United States

Greater access to alcohol has been widely found to be associated with many negative outcomes including violence perpetration. This study examines the relationship between alcohol outlet density, alcohol use, and intimate partner violence (IPV) victimization among young women in the United States. A direct association between alcohol outlet density in one's neighborhood and the likelihood of IPV victimization was examined. Data were from Wave III of the National Longitudinal Study of Adolescent Health (Add Health), which followed a nationally representative sample of adolescents into adulthood. Participants were young adult females age 18 to 26 at Wave III. Of the 4,571 female respondents who reported a current heterosexual relationship and had IPV data, 13.2% reported having been the victim of physical violence only and 6.5% experienced sexual only or physical and sexual violence in the relationship during the past year. In the regression models tested, there was no significant direct association between neighborhood alcohol outlet density and IPV victimization nor was there an association between outlet density and drinking behaviors, thus eliminating the possibility of an indirect association. Results of fully adjusted models indicate females who drank heavily, whether infrequently or frequently, were at significant risk for experiencing sexual only IPV or sexual and physical IPV. Asians and Native Americans were at significantly greater odds of experiencing sexual only or sexual and physical IPV compared with non-Hispanic Whites, while non-Hispanic Blacks were at significantly greater odds for physical only IPV. We conclude that a continuous measure of alcohol outlet density was not associated with IPV in models controlling for individual and other neighborhood characteristics. Young women who drink heavily, whether infrequently or frequently, have greater odds of experiencing sexual only or sexual and physical compared to abstainers. Similar to previous study findings, young women living with or married to their partner were at far greater risk of experiencing physical only and/or sexual only or sexual and physical IPV. The study adds to the growing body of literature that examines how community characteristics such as outlet density influence the likelihood of IPV.     

Calculating likelihood ratios for a mixed DNA profile when a contribution from a genetic relative of a suspect is proposed

This technical note describes a practical method for evaluating evidence in the case of a two person conditioned DNA mixture where the defence proposition is that the unknown contributor is genetically related to the suspect. A conditioned mixture is one where the presence of DNA from one of two individuals is accepted by both prosecution and defence. A typical example would be a vaginal swab in an alleged rape case, where the presence of the complainant's DNA would be expected and samples have been taken from the complainant and a suspect. Much has been written about the interpretation of such mixtures and the calculation of the conditional genotype probabilities that must be carried out. In general, such treatments assume that the unknown contributor, under the defence proposition, is unrelated to the known individuals. In this paper, we consider the case where the defence proposition is that the unknown contributor is genetically related to the suspect. We describe a method, incorporating a flow chart and reference tables that facilitate manual calculations of the likelihood ratio for several postulated genetic relationships.     

The United Kingdom and Ireland association of forensic toxicologists forensic toxicology laboratory guidelines (2018)

In 2010, the United Kingdom and Ireland Association of Forensic Toxicologists (UKIAFT) created forensic toxicology laboratory guidelines. This represents a revision of those guidelines as a result of the changing toxicological and technical landscape.     

Psychophysiological Responses of People with Psychopathic Tendencies to the Concealed Information Test

This study was designed to investigate differences in psychophysiological responses among individuals with psychopathic tendencies. A total 40 students were participated and were divided into two groups based on Levenson Self‐Report Psychopathy Scale (LSRP) scores: a high psychopathic tendency group selected from the top 5% of LSRP scores, and a low psychopathic tendency group selected from the bottom 5% of LSRP scores. All participants were instructed to perform a mock crime and complete the concealed information test (CIT). Results indicate that significant differences between crime‐relevant questions and irrelevant questions were observed for respiration line length and skin conductance response in both groups, but heart rate did not significantly differ between groups. There were no differences in psychophysiological responses between the groups. In conclusion, CIT was found to be an effective method for detecting crime‐relevant information in individuals with psychopathic tendencies.     

Political Culture and Corporal Punishment in Public Schools

The use of corporal punishment in public elementary and secondaryschools was found to correlate with Sharkansky's political cultureindex. This is true not only for the simple correlation forwhich Pearson's r = 0.749 but also for correlations obtainedafter controlling for region.     

Biasing effects of pretrial publicity on judicial decisions

In a four-factor design, the effects on judicial decisions of sample (102 students versus 100 nonstudents), sex of subject, pretrial publicity (damaging and relevant versus irrelevant), and judge's instructions (warning to disregard pretrial publicity versus a neutral statement) were examined. Results indicated that sample and judge's instructions had no effects on verdicts, recommendations for sentencing, or ratings of the strength of the prosecution and defenses' cases. Pretrial publicity, however, exerted a strong influence on verdicts and ratings of the prosecution's case, particularly among females. It is suggested that pretrial publicity may serve to affect evaluations of the evidence presented at the trial.