The evidential strength of a combination of corresponding class features in tire examination.

Tire marks are an important type of forensic evidence as they are frequently encountered at crime scenes. When the tires of a suspect's car are compared, the evidence can be very strong if so-called 'acquired features' are observed to correspond. When only 'class characteristics' such as parts of the tire pattern are observed to correspond, it is obvious that many other tires will exist that also correspond, and so this evidence is usually considered very weak or is simply ignored.

Firearm examination: Examiner judgments and computer-based comparisons.

Forensic firearm examination provides the court of law with information about the source of fired cartridge cases. We assessed the validity of source decisions of a computer-based method and of 73 firearm examiners who compared breechface and firing pin impressions of 48 comparison sets. We also compared the computer-based method's comparison scores with the examiners' degree-of-support judgments and assessed the validity of the latter.

Cognitive biases in the peer review of bullet and cartridge case comparison casework: A field study.

Objective: Forensic judgments and their peer review are often the result of human assessment and are thus subjective and prone to bias. This study examined whether bias affects forensic peer review.

Hypotheses: We hypothesized that the probability of disagreement between two forensic examiners about the proposed conclusion would be higher with "blind" peer review (reviewer saw only the first examiner's comparison photos) than with "non-blind" peer review (reviewer also saw the first examiner's interpretation and proposed conclusion).

Paediatric femur fractures-the value of contextual information on judgement in possible child abuse cases: are we bias?

The majority of paediatric femur fractures result from accidental trauma; however, it is important to consider non-accidental trauma, especially in pre-ambulatory children. We study whether irrelevant contextual information subconsciously influences conclusions of healthcare professionals with respect to whether observations provide evidence for non-accidental trauma. A survey with nine radiographs of femur shaft fractures was designed.

Assessing the frequency of general fingerprint patterns by fingerprint examiners and novices.

The rarity of general fingerprint patterns should be taken into account in the assessment of fingerprint evidence to provide a more complete assessment of fingerprint evidence than when only considering the minutiae. This should be done because, the rarer the corresponding pattern, the stronger the support for the hypothesis that the fingermark stems from the same source as the reference fingerprint. Fingerprint examiners' experience should enable them to provide meaningful assessments of the frequencies of these general patterns according to the theories of perceptual learning, exemplar theory of categorization and visual statistical learning.

Postmortem Computed Tomography in Firearm Homicides: A Retrospective Case Series.

Postmortem computed tomography (PMCT) is integrated into the evaluation of decedents in several American medical examiner offices and medicolegal death investigative centers in many other countries. We retrospectively investigated the value of PMCT in a series of firearm homicide cases from a statewide centralized medical examiner's office that occurred during 2016. Autopsies were performed or supervised by board-certified forensic pathologists who reviewed the PMCT scans prior to autopsy.

Validity and reliability of forensic firearm examiners.

Forensic firearm examiners compare the features in cartridge cases to provide a judgment addressing the question about their source: do they originate from one and the same or from two different firearms? In this article, the validity and reliability of these judgments is studied and compared to the outcomes of a computer-based method. The features we looked at were the striation patterns of the firing pin aperture shear marks of four hundred test shots from two hundred Glock pistols, which were compared by a computer-based method. Sixty of the resulting 79,800 comparisons were shown to 77 firearm examiners.

Numerical likelihood ratios outputted by LR systems are often based on extrapolation: When to stop extrapolating?

A recent trend in forensic science is the development of objective, automated systems for the comparison of trace and reference material that give as output numerical likelihood ratios (LRs). For well discriminating LR systems, often the probability of the evidence given one or the other hypothesis depends on the density from the tail of a probability distribution. The models for probability distributions are trained by data.

Ricochet Behavior on Glass-Critical Ricochet Angles, Ricochet Angles, and Deflection Angles.

For shooting scene reconstruction purposes, knowledge about the ricochet behavior of bullets provides valuable information. In this study, the critical ricochet angles of four cartridge types were established on plain float glass. The estimates of the critical ricochet angles varied between cartridge types and were 21.

Effects of CBRN decontaminants in common use by first responders on the recovery of latent fingerprints--assessment of the loss of ridge detail on glass.

Following a CBRN incident, first responders use decontamination procedures to reduce the risk of exposure. The effect of decontamination on forensic trace material has, however, not been fully examined. This study sought to evaluate the effect of five different physical or chemical decontamination materials on the recovery of latent fingerprints.

Determination of efficacy of fingermark enhancement reagents; the use of propyl chloroformate for the derivatization of fingerprint amino acids extracted from paper.

The analysis of the constituents of fingerprints has been described numerous times, mainly with the purpose of determining the aging effect on fingerprints or showing the differences between donors or groups of donors. In this paper we describe the use of derivatized amino acids to determine the efficacy of the visualization reagents 1,8-diazafluoren-9-one (DFO) and ninhydrin. At present certain conditions are used for the application of these reagents, as determined by trial-and-error investigations, to the effect on fingerprints.

Improving the point of origin determination in bloodstain pattern analysis.

In bloodstain pattern analysis, it is important to know the point of origin (PO) of an impact pattern. This point can be estimated by means of the stringing method, the tangent method, or by commercially available computer programs. In this study, the accuracy of two computer programs was investigated under different conditions.

Opening the psychological black box in genetic counseling. The psychological impact of DNA testing is predicted by the counselees' perception, the medical impact by the pathogenic or uninformative BRCA1/2-result.

Background: It has been hypothesized that the Outcomes of DNA testing (O) are better predicted and/or mediated by the counselees' Perception P) than by the actually communicated genetic Information (I). In this study, we aimed at quantifying the effect that perception has in genetic counseling for hereditary breast/ovarian cancer.

Methods: Two hundred and four women, who had previously been tested for BRCA1/2, participated in a retrospective questionnaire study; 93% had cancer.

Correction to Tzidony and Ravreby (1992): a statistical approach to drug sampling: a case study.

In 1992, Tzidony and Ravreby presented a confidence interval for the total weight of a seizure of illicit drugs present in a population. Their approach has subsequently been applied by several researchers in the field. The formula on which their approach is based does, however, not fully take into account the proportion of drug units found in the sample.

Does suggestive information cause a confirmation bias in bullet comparisons?

Several researchers have argued that the confirmation bias, the tendency to selectively gather and process information such that it fits existing beliefs, is a main threat to objective forensic examinations. The goal of the present study was to empirically investigate whether examiners making bullet comparisons are indeed vulnerable to this bias. In the first experiment, six qualified examiners evaluated 6 sets of bullets that were presented to them twice.

Comparison of frequentist methods for estimating the total weight of consignments of drugs.

A topic in forensic statistics is the estimation of the total weight of consignments of drugs based on subsamples of which a certain fraction may not contain drugs at all. The frequentist approach to this concentrates on obtaining confidence intervals for the total weight, based on estimation of the fraction of drugs and the mean and variance of the weights of drug units. The current study shows that the resulting confidence intervals are basically unreliable, since they are based on an underestimation of the variation of the underlying statistical process.

Risk factors occurring during pregnancy and birth in relation to brain functioning and child's anxiety.

Objective: This study examined whether the most objective risk factors during pregnancy (prenatal) and delivery (perinatal) precede child's anxiety, and whether these factors exerted their influence via child's non-specific cerebral functioning.

Method: Median-anxious (n=82) and high-anxious (n=188) children (8-12), enrolled via the use of an anxiety screening questionnaire. Mothers were interviewed on pre-/perinatal risk factors, and children completed a visuospatial copying task.

Predicting growth curves of early childhood externalizing problems: differential susceptibility of children with difficult temperament.

Using an accelerated longitudinal design, the development of externalizing problems from age 2 to 5 years was investigated in relation to maternal psychopathology, maternal parenting, gender, child temperament, and the presence of siblings. The sample consisted of 150 children selected at age 2-3 years for having high levels of externalizing problems. Parenting was measured using observational methods, and maternal reports were used for the other variables.