A mixed DNA profile controversy revisited

Semaan et al. (J Forensic Res, 2020, 11, 453) discuss a mock case “where eight different individuals [P₁ through P₈] could not be excluded in a mixed DNA analysis. Even though … expert DNA mixture analysis software was used.” Two of these are the true donors. The LRs reported are incorrect due to the incorrect entry of propositions into LRmix Studio. This forced the software to account for most of the alleles as drop-in, resulting in LRs 60–70 orders of magnitude larger than expected. P₁, P₂, P₄, P₅, and P₈ can be manually excluded using peak heights. This has relevance when using LRmix which does not use peak heights. We extend the work using the same two reference genotypes who were the true contributors as Semaan et al. (J Forensic Res, 2020, 11, 453). We simulate three two-donor mixtures with peak heights using these two genotypes and analyze using STRmix?. For the simulated 1:1 mixture, one of the non-donors’ LRs supported him being a contributor when no conditioning was used. When considered in combination with any other potential donors (i.e., with conditioning), this non-donor was correctly eliminated. For the 3:1 mixture, all results correctly supported that the non-donors were not contributors. The low-template 4:1 mixture LRs with no conditioning showed support for all eight profiles as donors. However, the results from pair-wise conditioning showed that only the two ground truth donors had LRs supporting that they were contributors to the mixture. We recommend the use of peak heights and conditioning profiles, as this allows better sensitivity and specificity even when the persons share many alleles.     

Using the Nondonor Distribution to Improve Communication and Inform Decision Making for Low LRs from Minor Contributors in Mixed DNA Profiles

The reporting of a likelihood ratio (LR) calculated from probabilistic genotyping software has become more popular since 2015 and has allowed for the use of more complex mixtures at court. The meaning of “inconclusive” LRs and how to communicate the significance of low LRs at court is now important. We present a method here using the distribution of LRs obtained from nondonors. The nondonor distribution is useful for examining calibration and discrimination for profiles that have produced LRs less than about 10⁴. In this paper, a range of mixed DNA profiles of varying quantity were constructed and the LR distribution considering the minor contributor for a number of nondonors was compared to the expectation given a calibrated system. It is demonstrated that conditioning genotypes should be used where reasonable given the background information to decrease the rate of nondonor LRs above 1. In all 17 cases examined, the LR for the minor donor was higher than the nondonor LRs, and in 12 of the 17 cases, the 99.9 percentile of the nondonor distribution was lower when appropriate conditioning information was used. The output of the tool is a graph that can show the position of the LR for the person of interest set against the nondonor LR distribution. This may assist communication between scientists and the court.     

Comparison of the variables affecting the recovery of DNA from common drinking containers

As the boundaries of forensic DNA profiling continue to expand, less obvious sources of biological evidence are being collected at crime scenes for DNA profiling. One example is the recovery of biological evidence from common drink containers, such as bottles and cans, which have been found at crime scenes. There are many variables that may have an impact on recovering a DNA profile from such exhibits. In this research, the effects of person to person variation, time, type of drink (including alcoholic and non-alcoholic beverages), and type of drink container, were assessed for their impact on the major analytical outcomes of the DNA process. The results show that the alpha-amylase activity varies from individual to individual and is reduced in the presence of some alcoholic drinks. A reasonable DNA yield was obtained from all samples, however, the concentrations exhibited significant person to person variation. The type of drink container influenced the DNA yield with cans giving a higher yield than bottles of the same drink type. To a reduced extent the presence or absence of alcohol affected the overall DNA yield and when partial or failed DNA profiles were produced they were more likely to be associated with alcoholic drinks than non-alcoholic drinks.     

From Victimization to Criminalization: General Strain Theory and the Relationship Between Poly-victimization and Delinquency

Although it is well established that victimization and delinquency are related, it is not clear how this relationship works, and victims and offenders are still often studied and treated as two distinct groups. General strain theory views victimization as a form of injustice, which can give rise to anger and eventually lead to delinquency. The authors examine victimization, in particular polyvictimization, as a criminogenic factor. Based on a sample of 1,400 youths 12–17 years old in Quebec (Canada), they examine polyvictimization in relation to delinquency as well as negative emotions that can result from victimization namely anger, depression, and posttraumatic stress. The findings show support for general strain theory and highlight the importance of anger for the relationship between victimization and juvenile delinquency.     

RESISTANCE TO VISITATION

The authors argue that current formulations of the problem of resistance to visitation in separation and divorce are conceptually weak because they fail to take into account the adversarial influence of the legal paradigm. First- and second-order change theory is used to clarify the problem, and a new formulation is proposed that shifts the focus from the parent and/or child exclusively to the resistance dynamic as a whole. General guidelines for intervention are proposed based on a holistic, participatory model that takes into account the tensions involved in working toward compliance while upholding the best interests of the child.     

What is procedural justice: Criteria used by Dutch victims to assess the fairness of criminal justice procedures

The study examines the meaning of procedural justice to Dutch victims of crime. Using victimological research and the group-value or relational model or procedural justice developed by Lind and Tyler, a model for procedural justice judgments is developed and tested using the structural equation model. Data used for the analysis consist of 221 interviews with victims regarding their experience with the public prosecution. Although the emerging model differs from that of Lind and Tyler, results support Lind and Tyler's assertion that procedural justice judgments are normative and not instrumental. Victims are particularly concerned about being treated with dignity and respect and are not interested in influencing the outcome of their case.     

Victim Policy Transfer: Learning From Each Other

This paper looks at the recent introduction of victim impact statements in several European countries. It asks whether victim impact statements are a positive addition to victim policy and practice in Europe and examines the challenges of adapting to the civil legal tradition a tool that was developed in a common law country.     

Recovery of trace DNA and its application to DNA profiling of shoe insoles

In recent years, the analysis of trace amounts of DNA has become a necessary and useful forensic tool. DNA profiles can be obtained from items that have been worn or handled, due to the presence of transferred DNA derived from skin cells. Shoeprints collected from crime scenes that match a suspects shoe can link a shoe to the crime scene. A DNA profile from inside the shoe can link a wearer to a shoe thus increasing the evidential value of the forensic evidence. In this work, variation in the amount of DNA recovered from hands and feet of different individuals is investigated. Sites for sampling DNA from shoe insoles are compared and a protocol for the subsequent sampling and extraction is developed. Finally, a case study is described where DNA analysis of shoe insoles has provided forensic evidence.     

Procedural Justice and Dutch Victim Policy

This paper opens with a brief discussion of the traditional role of the victim in the criminal justice system and the changes which have been made in the Netherlands in order to improve the position of victims of crime. In addition, the author discusses the arguments put forward by policymakers and examines the implementation of victim policy. Next, procedural justice is introduced as a theory from which one could consider the possible impact of victims' experiences in the criminal justice system on their relationship with the justice system. The author goes on to present research which examines the impact of procedural justice on victims' attitudes towards legal authorities. The paper closes with a discussion of the importance of procedural justice issues for criminal justice policymakers and legal practitioners.