Recommendations of the DNA Commission of the International Society for Forensic Genetics (ISFG) on short tandem repeat sequence nomenclature.

The DNA Commission of the International Society for Forensic Genetics (ISFG) has developed a set of nomenclature recommendations for short tandem repeat (STR) sequences. These recommendations follow the 2016 considerations of the DNA Commission of the ISFG, incorporating the knowledge gained through research and population studies in the intervening years. While maintaining a focus on backward compatibility with the CE data that currently populate national DNA databases, this report also looks to the future with the establishment of recommended minimum sequence reporting ranges to facilitate interlaboratory comparisons, automated solutions for sequence-based allele designations, a suite of resources to support bioinformatic development, guidance for characterizing new STR loci, and considerations for incorporating STR sequences and other new markers into investigative databases.

'Low' LRs obtained from DNA mixtures: On calibration and discrimination performance of probabilistic genotyping software.

The validity of a probabilistic genotyping (PG) system is typically demonstrated by following international guidelines for the developmental and internal validation of PG software. These guidelines mainly focus on discriminatory power. Very few studies have reported with metrics that depend on calibration of likelihood ratio (LR) systems.

A study into the natural occurrence of inorganic ions relevant to forensic explosives investigations on human hands.

The natural occurrence of 16 inorganic ions relevant to forensic explosives investigations on human hands was studied to support the evaluation of activity-level propositions when such traces are found on the hands or in the fingerprints of a suspect. A total of 594 hand swab extracts from 297 participants throughout Europe and the United States of America were analyzed using Ion Chromatography - Mass Spectrometry. The data provides a reference framework for future covert investigations and forensic casework.

Prevalence of male DNA on female worn undergarments. How small datasets may support robust opinions in activity level evaluative reporting.

In cases of sexual assault, the interpretation of biological traces on clothing, and particularly undergarments, may be complex. This is especially so when the complainant and defendant interact socially, for instance as (ex-)partners or by co-habitation. Here we present the results from a study where latent male DNA on female worn undergarments is recovered in four groups with different levels of male-female social interaction.

Applicability of the Madymo Pedestrian Model for forensic fall analysis.

Forensic reconstruction and scenario evaluation are crucial in investigations of suspicious deaths related to falls from a height. In such cases, distinguishing between accidental falls, being pushed or jumping is an important but difficult task, since objective methods to do so are currently lacking. This paper explores the possibility of repurposing a passive rigid body model of a human from commercially available crash simulation software for forensic reconstruction and scenario evaluation of humans dropping from heights.

Crystal clear connections - database matching unknown glass fragments to reference glass from ATM explosions.

This paper introduces the concept of an operational reference glass database, specifically designed for broken glass fragments from ATM attacks, jewelry store robberies, and ramraids on high-end clothing stores. The database, initiated in 2014, is used to compare glass traces from organized crews involved said criminal activities. Utilizing LA-ICPMS, this study establishes a methodology for collecting reference glass samples from the scenes of the aforementioned crimes, thus creating a comprehensive database containing over 3500 reference glass samples from crime scenes.

An open-source, three-dimensional growth model of the mandible.

The available reference data for the mandible and mandibular growth consists primarily of two-dimensional linear or angular measurements. The aim of this study was to create the first open-source, three-dimensional statistical shape model of the mandible that spans the complete growth period. Computed tomography scans of 678 mandibles from children and young adults between 0 and 22 years old were included in the model.

An overview of log likelihood ratio cost in forensic science - Where is it used and what values can we expect?

There is increasing support for reporting evidential strength as a likelihood ratio (LR) and increasing interest in (semi-)automated LR systems. The log-likelihood ratio cost () is a popular metric for such systems, penalizing misleading LRs further from 1 more.  = 0 indicates perfection while  = 1 indicates an uninformative system.

ENFSI 2022 multidisciplinary collaborative exercise: organisation and outcomes.

The use of collaborative exercises (CE) and proficiency tests (PT) as part of the governance programme for any forensic science laboratory has become commonplace and recommended by several international organisations. Traditionally these have been discipline-specific exercises testing a laboratory's ability in a single area of forensic science. However, the "real" world is normally more complex and, in many instances, forensic material must be examined for a number of different evidence types.

From data to a validated score-based LR system: A practitioner's guide.

Likelihood ratios (LRs) are a useful measure of evidential strength. In forensic casework consisting of a flow of cases with essentially the same question and the same analysis method, it is feasible to construct an 'LR system', that is, an automated procedure that has the observations as input and an LR as output. This paper is aimed at practitioners interested in building their own LR systems.

Improved likelihood ratios for face recognition in surveillance video by multimodal feature pairing.

In forensic and security scenarios, accurate facial recognition in surveillance videos, often challenged by variations in pose, illumination, and expression, is essential. Traditional manual comparison methods lack standardization, revealing a critical gap in evidence reliability. We propose an enhanced images-to-video recognition approach, pairing facial images with attributes like pose and quality.

A practical treatment of sensitivity analyses in activity level evaluations.

Evaluations of forensic observations considering activity level propositions are becoming more common place in forensic institutions. A measure that can be taken to interrogate the evaluation for robustness is called sensitivity analysis. A sensitivity analysis explores the sensitivity of the evaluation to the data used when assigning probabilities, or to the level of uncertainty surrounding a probability assignment, or to the choice of various assumptions within the model.

Extracorporeal bullet trajectory determination from scanned phantoms with bullet defects.

Shots with two different calibres (0.32 Auto and 9 mm Luger) were fired through phantoms that simulated human torsos, mounted on undercarriages with witness panels. The perforated phantoms were scanned with computed tomography (Siemens) using 80 kV and 140 kV and a slice thickness of 1 mm.

Modeling of inflicted head injury by shaking trauma in children: what can we learn? : Update to parts I&II: A systematic review of animal, mathematical and physical models.

Inflicted shaking trauma can cause injury in infants, but exact injury mechanisms remain unclear. Controversy exists, particularly in courts, whether additional causes such as impact are required to produce injuries found in cases of (suspected) shaking. Publication rates of studies on animal and biomechanical models of inflicted head injury by shaking trauma (IHI-ST) in infants continue rising.

Single-cell investigative genetics: Single-cell data produces genotype distributions concentrated at the true genotype across all mixture complexities.

In the absence of a suspect the forensic aim is investigative, and the focus is one of discerning what genotypes best explain the evidence. In traditional systems, the list of candidate genotypes may become vast if the sample contains DNA from many donors or the information from a minor contributor is swamped by that of major contributors, leading to lower evidential value for a true donor's contribution and, as a result, possibly overlooked or inefficient investigative leads. Recent developments in single-cell analysis offer a way forward, by producing data capable of discriminating genotypes.

CSI-CSI: Comparing several investigative approaches toward crime scene improvement.

Crime scene investigations are highly complex environments that require the CSI to engage in complex decision-making. CSIs must rely on personal experience, context information, and scientific knowledge about the fundamental principles of forensic science to both find and correctly interpret ambiguous traces and accurately reconstruct a scene. Differences in CSI decision making can arise in multiple stages of a crime scene investigation.

The relationship between pellet size and shotgun dispersion patterns.

When reconstructing a shooting incident with a shotgun, the muzzle-to-target distance can be determined by relating the size of a dispersion pattern found on a crime scene to that of test shots. Ideally, the test shots are performed with the weapon and ammunition that were used in the incident. But sometimes examiners will have to resort to alternatives, such as using cartridges of the same brand and type but with another pellet size.

The systemic error in the vertical component of handgun bullet trajectory reconstructions.

Establishing the path or trajectory of a fired bullet is an often recurring part of shooting incident reconstruction. The current study describes how gravitational pull causes a systemic error on the vertical component of a trajectory reconstruction. Bullet drop, drop angle, and vertical offset are explained and calculated for 10 different handgun/ammunition combinations over a range of distances up to 100 m.

Postmortem redistribution of amphetamines and benzodiazepines in humans: Important variables that might be influencing the central blood / peripheral blood ratio.

Introduction: The primary objective of postmortem forensic toxicology is to determine if toxicological substances detected in bodily material of victims have contributed to the death of the victim. Interpretation of postmortem drug concentrations is hindered by the fact that time and site dependent variations in postmortem drug concentrations occur, as a result of postmortem redistribution (PMR). An often-used marker for the occurrence of PMR, is the cardiac blood concentration/peripheral blood concentration ratio (C/P ratio) of a drug.

Automated interpretation of comparison scores for firearm toolmarks on cartridge case primers.

An automated approach for evaluating the strength of the evidence of firearm toolmark comparison results is presented for a common source scenario. First, comparison scores are derived describing the similarity of marks typically encountered on the primer of fired cartridge cases: aperture shear striations as well as breechface and firing pin impressions. Subsequently, these scores are interpreted using reference distributions of comparison scores obtained for representative known matching (KM) and known non-matching (KNM) ballistic samples in a common source, score-based likelihood ratio (LR) system.

Measuring the rarity of core-delta distances in fingerprint patterns in the Dutch population.

In latent print examination, a conclusion on an individualization is primarily based on the presence of corresponding minutiae. Depending on the level of correspondence between the minutiae on the fingermark and on the reference print, a match is concluded. However, a fingermark is analyzed on all three levels: general pattern combined with core-delta distance, minutiae, and third-level detail.

Skeletal age estimation of living adolescents and young adults: A pilot study on conventional radiography versus magnetic resonance imaging and staging technique versus atlas method.

Objective: To compare conventional radiography (CR) and magnetic resonance imaging (MRI) of the left hand/wrist and both clavicles for forensic age estimation of adolescents and young adults.

Materials And Methods: CR and MRI were prospectively conducted in 108 healthy Caucasian volunteers (52 males, 56 females) aged 16 to 21 years. Skeletal development was assessed by allocating stages (wrist, clavicles) and atlas standards (hand/wrist).

Data strategies in forensic automatic speaker comparison.

Automatic speaker recognition (ASR) is a method used in forensic speaker comparison (FSC) casework. It needs collections of audio data that are representative of the case audio in order to perform reference normalization and to train a score-to-LR function. Audio from a certain minimum number of speakers is needed for each of those purposes to obtain relatively stable performance of ASR.