A Re-examination of the Effects of Biased Lineup Instructions in Eyewitness Identification

A meta-analytic review of research comparing biased and unbiased instructions in eyewitness identification experiments showed an asymmetry; specifically, that biased instructions led to a large and consistent decrease in accuracy in target-absent lineups, but produced inconsistent results for target-present lineups, with an average effect size near zero (Steblay, 1997). The results for target-present lineups are surprising, and are inconsistent with statistical decision theories (i.e., Green & Swets, 1966). A re-examination of the relevant studies and the meta-analysis of those studies shows clear evidence that correct identification rates do increase with biased lineup instructions, and that biased witnesses make correct identifications at a rate considerably above chance. Implications for theory, as well as police procedure and policy, are discussed.     

STR analysis of artificially degraded DNA-results of a collaborative European exercise

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.     

Differences in trauma symptoms and family functioning in intra-and extrafamilial sexually abused adolescents

This study investigated to what extent abuse-related symptoms and family functioning are related to intra- or extrafamilial sexual abuse. One hundred adolescents (12 to 18 years old) were recruited shortly after disclosure of the abuse. Information from the participants was obtained through self-report questionnaires and a semistructured interview. Fifty-three percent of the adolescents reported clinically significant symptoms. Data did not support the idea that intrafamilial sexually abused adolescents report more symptoms than extrafamilial sexually abused adolescents. Type of abuse did not account for the differences and variety of reported symptoms or for differences in family functioning. Family functioning-in particular, lack of cohesion- was an independent contributor to internalizing trauma-related problems.     

Death by chainsaw: fatal kickback injuries to the neck

Each year over 3 million new chainsaws are sold in the United States. The operation of these newer saws combined with the millions of older chainsaws in circulation results in over 28,000 chainsaw-related injures annually. The majority of the injuries involve the hands and lower extremities with less than 10% involving injuries to the head and neck regions. Deaths while operating a chainsaw are extremely rare. The most common hazards associated with chainsaws are injuries caused by kickback, pushback, and pull-in. Kickback is the most common and poses the greatest hazard. Kickback occurs when the rotating chain is stopped suddenly by contact with a more solid area throwing the saw rapidly backward toward the operator. The cause of most injuries can be traced to improper use of the saw or poor judgment on part of the operator. We present two fatal chainsaw deaths; one with an older style saw, and the other with a modern type. In both cases the victims died from fatal injuries received to the neck region from a chainsaw kickback. The first case involved a 49-year-old white male operating an older style chainsaw with limited safety features. The second case involved a 38-year old white male who was operating a newer model chainsaw equipped with a low kickback chain in an unsafe manner.     

Cardiac concussion: definition, differential diagnosis, and cases presentation and the legal ramification of a misdiagnosis

A cardiac concussion is caused by a sudden, nonpenetrating, localized impact to the chest that is theorized to result in almost simultaneous sudden death from a disruption to the conductive system. The detailed external/internal forensic examination of the body reveals no evidence of structural, pathologic, or histologic signs of trauma to the heart. A cardiac concussion is a rare and often overlooked cause of sudden death. This type of sudden death is typically seen among younger individuals participating in sports involving projectiles and, to a lesser degree, where collisions occur. Cardiac concussions are clinically, pathologically, and chemically different from a cardiac contusion. The objective of this paper will be to define cardiac concussion, differentiate between cardiac concussion and cardiac contusion, and describe the clinical and pathologic features of a 32-year-old white male who died of a cardiac concussion following a collision with a catcher during a softball game. The civil ramification of incorrectly diagnosing the manner of death in cases of death involving a cardiac concussion will also be addressed.     

Interpretation of a 3,4-methylenedioxymethamphetamine (MDMA) blood level: discussion by means of a distribution study in two fatalities

The amphetamine derivative 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy" is a currently used or abused designer drug and fatalities are frequently encountered in forensic practice. However, the question remains open whether an MDMA blood level can be toxic or even potentially lethal. In order to provide insight in the interpretation of a detected MDMA concentration, the distribution of MDMA and its metabolite 3,4-methylenedioxyamphetamine (MDA) in various body fluids and tissues was studied and discussed in two different fatalities. Apart from peripheral blood samples (such as femoral and subclavian blood), various blood samples obtained centrally in the human body and several body fluids (such as vitreous humour) were examined. In addition, various tissues such as cardiac muscle, lungs, liver, kidneys, and brain lobes were analysed. In contrast to the peripheral blood levels, high MDMA and MDA levels were found in cardiac blood and the majority of the organs, except for the abdominal adipose tissue. The high concentrations observed in all lung lobes, the liver and stomach contents indicate that post-mortem redistribution of MDMA and MDA into cardiac blood can occur and, as a result, blood sampled centrally in the body should be avoided. Therefore, our data confirm that peripheral blood sampling remains "the golden standard". In addition, a distinct difference in peripheral blood MDMA concentrations in our two overdose cases was established (namely 0.271 and 13.508 microg/ml, respectively). Furthermore, our results suggest that, if a peripheral blood sample is not available and when putrefaction is not too pronounced, vitreous humour and iliopsoas muscle can be valuable specimens for toxicological analysis. Finally, referring to the various mechanisms of death following amphetamine intake, which can result in different survival times (e.g. cardiopulmonary complications versus hyperthermia), the anatomo-pathological findings and the toxicological results should be considered as a whole in arriving at a conclusion.