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.     

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.