Validating TrueAllele® DNA mixture interpretation

Abstract: DNA mixtures with two or more contributors are a prevalent form of biological evidence. Mixture interpretation is complicated by the possibility of different genotype combinations that can explain the short tandem repeat (STR) data. Current human review simplifies this interpretation by applying thresholds to qualitatively treat STR data peaks as all‐or‐none events and assigning allele pairs equal likelihood. Computer review, however, can work instead with all the quantitative data to preserve more identification information. The present study examined the extent to which quantitative computer interpretation could elicit more identification information than human review from the same adjudicated two‐person mixture data. The base 10 logarithm of a DNA match statistic is a standard information measure that permits such a comparison. On eight mixtures having two unknown contributors, we found that quantitative computer interpretation gave an average information increase of 6.24 log units (min = 2.32, max = 10.49) over qualitative human review. On eight other mixtures with a known victim reference and one unknown contributor, quantitative interpretation averaged a 4.67 log factor increase (min = 1.00, max = 11.31) over qualitative review. This study provides a general treatment of DNA interpretation methods (including mixtures) that encompasses both quantitative and qualitative review. Validation methods are introduced that can assess the efficacy and reproducibility of any DNA interpretation method. An in‐depth case example highlights 10 reasons (at 10 different loci) why quantitative probability modeling preserves more identification information than qualitative threshold methods. The results validate TrueAllele^® DNA mixture interpretation and establish a significant information improvement over human review.     

Who's flying the plane: serotonin levels, aggression and free will

The present paper addresses the philosophical problem raised by current causal neurochemical models of impulsive violence and aggression: to what extent can we hold violent criminal offenders responsible for their conduct if that conduct is the result of deterministic biochemical processes in the brain. This question is currently receiving a great deal of attention among neuroscientists, legal scholars and philosophers. We examine our current knowledge of neuroscience to assess the possible roles of deterministic factors which induce impulsive aggression, and the extent to which this behavior can be controlled by neural conditioning mechanisms. Neural conditioning mechanisms, we suggest, may underlie what we consider the basis of responsible (though not necessarily moral) behavior: the capacity to give and take reasons. The models we first examine are based in part upon the role played by the neurotransmitter, serotonin, in the regulation of violence and aggression. Collectively, these results would appear to argue in favor of the view that low brain serotonin levels induce impulsive aggression which overrides mechanisms related to rational decision making processes. We next present an account of responsibility as based on the capacity to exercise a certain kind of reason-responsive control over one's conduct. The problem with such accounts of responsibility, however, is that they fail to specify a neurobiological realization of such mechanisms of control. We present a neurobiological, and weakly determinist, framework for understanding how persons can exercise guidance control over their conduct. This framework is based upon classical conditioning of neurons in the prefrontal cortex that allow for a decision making mechanism that provides for prefrontal cortical control of the sites in the brain which express aggressive behavior that include the hypothalamus and midbrain periaqueductal gray. The authors support the view that, in many circumstances, neural conditioning mechanisms provide the basis for the control of human aggression in spite of the presence of brain serotonin levels that might otherwise favor the expression of impulsive aggressive behavior. Indeed if those neural conditioning mechanisms underlie the human capacity to exercise control, they may be the neural realization of reason-responsiveness generally.     

Asia-Pacific news

This column provides a country by country analysis of the latest legal developments, cases and issues relevant to the IT, media and telecommunications’ industries in key jurisdictions across the Asia Pacific region. The articles appearing in this column are intended to serve as ‘alerts’ and are not submitted as detailed analyses of cases or legal developments.     

In courtroom 7--the Children's Koori Court at work: findings from an evaluation

This article reports some of the findings of an evaluation of the Children's Koori Court (CKC)--the first legislated effort in Australia to involve the Indigenous community in the sentencing of young Aboriginal offenders as a strategy for reducing their overrepresentation in the juvenile justice system. A prominent feature of this court of summary jurisdiction is that the presiding magistrate, while remaining the sentencing authority, is assisted by Aboriginal Elders. This article focuses on the evaluation findings that were derived from observations of the CKC in action. They indicate that the operational objective of cultural responsiveness was realized. They also point to realization of the community-building goal-fostering Indigenous ownership of the administration of the law. Little slippage was found between the CKC's design and operation, although some areas of improvement were identified. Nevertheless, the scope for the CKC by itself to significantly reduce overrepresentation is limited.     

Asia-Pacific news

This column provides a country by country analysis of the latest legal developments, cases and issues relevant to the IT, media and telecommunications’ industries in key jurisdictions across the Asia Pacific region. The articles appearing in this column are intended to serve as ‘alerts’ and are not submitted as detailed analyses of cases or legal developments.     

Asia-Pacific news

This column provides a country by country analysis of the latest legal developments, cases and issues relevant to the IT, media and telecommunications’ industries in key jurisdictions across the Asia-Pacific region. The articles appearing in this column are intended to serve as ‘alerts’ and are not submitted as detailed analyses of cases or legal developments.     

Asia-Pacific news

This column provides a country by country analysis of the latest legal developments, cases and issues relevant to the IT, media and telecommunications’ industries in key jurisdictions across the Asia-Pacific region. The articles appearing in this column are intended to serve as ‘alerts’ and are not submitted as detailed analyses of cases or legal developments.     

Temporal variation of oxygen isotope ratios (δ18O) in drinking water: implications for specifying location of origin with human scalp hair

Previous work suggests that δ(18)O values of human hair can be used to constrain the region-of-origin of unknown individuals, but robust assessments of uncertainties in this method are lacking. Here we assess one source of uncertainty - temporal variation in the δ(18)O value of drinking water - using a monthly tap water survey of δ(18)O to develop geospatial models (i.e., maps) of the intra-annual variation (seasonality) in tap water δ(18)O for the contiguous USA. Temporal variation in tap water δ(18)O was correlated with water-supply type, and was related to geographic patterns of precipitation δ(18)O seasonality and water residence time. The maps were applied in a Bayesian framework to identify the geographic origin of an unidentified woman found in Utah, based on measured δ(18)O of scalp hair. The results are robust in specifying parts of the western USA as the most likely region-of-origin. Incorporation of tap water δ(18)O seasonality in the analysis reduces the precision of geographic assignments, but other sources of uncertainty (e.g., spatial interpolation uncertainty) have an equal or larger effect.     

Police-monitored CCTV cameras in Newark, NJ: A quasi-experimental test of crime deterrence

We present a test of the crime-deterrent effect of police-monitored street-viewing CCTV cameras using viewsheds of areas that were visible by cameras via direct line-of-sight and that were digitized using easily replicable methods, Google Maps, and standard GIS tools. A quasi-experimental research design, using camera installation sites and randomly selected control sites, assessed the impact of CCTV on the crimes of shootings, auto thefts, and thefts from autos in Newark, NJ, for 13 months before and after camera installation dates. Strategically-placed cameras were not any different from randomly-placed cameras at deterring crime within their viewsheds; there were statistically significant reductions in auto thefts within viewsheds after camera installations; there were significant improvements to location quotient values for shootings and auto thefts after camera installations. There was no significant displacement and there was a small diffusion of benefits, which was greater for auto thefts than shootings. The system of cameras in Newark is not as efficient as it could be at deterring certain street crimes; some camera locations are significantly more effective than others. Results of a system-wide evaluation of CCTV cameras should not be the only basis for endorsing or contesting the use of CCTV cameras for crime control or prevention within a city. Future research should test whether the effectiveness of CCTV cameras are dependent upon the micro-level attributes of environments within which they are installed.