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. For this reason, the relationship between pellet size and shotgun dispersion patterns was studied with both lead and steel shotgun pellets. Cartridges were loaded with identical cartridge cases, powder charges, and wads but with different pellet sizes, below size B. The cartridges were fired, and the dispersion patterns at 5 m in front of the muzzle were measured and compared. The results provide strong support for the proposition that shotgun dispersion patterns with both lead and steel shot increase with decreasing pellet size if all other relevant parameters are kept equal. The results also provide an indicative measure of the magnitude of the effect. Pattern sizes were approximately 1.7 times larger with #9 than with #0 lead shot and 1.4 times larger with #9 than with #1 steel shot. The differences between consecutive shot sizes were generally smaller. This means that cartridges of equal brand and type but with the next nearest shot number can be used for a muzzle-to-target distance determination, keeping the information of the current study in mind in the final interpretation of the results.
DOCUMENT
The paper introduced an automatic score detection model using object detection techniques. The performance of sevenmodels belonging to two different architectural setups was compared. Models like YOLOv8n, YOLOv8s, YOLOv8m, RetinaNet-50, and RetinaNet-101 are single-shot detectors, while Faster RCNN-50 and Faster RCNN-101 belong to the two-shot detectors category. The dataset was manually captured from the shooting range and expanded by generating more versatile data using Python code. Before the dataset was trained to develop models, it was resized (640x640) and augmented using Roboflow API. The trained models were then assessed on the test dataset, and their performance was compared using matrices like mAP50, mAP50-90, precision, and recall. The results showed that YOLOv8 models can detect multiple objects with good confidence scores.
DOCUMENT
In this study, the construction of rumour on Twitter during a specific crisis is analysed from a discursive psychological perspective. This perspective treats psychological concepts such as identities as discursive constructions. The selected case is the robbery of a jewellery store in Deurne, a village in the Netherlands. The jeweller’s wife was said to have shot two of the robbers. Although this fact was not officially confirmed, people used particular discursive strategies to present the act of the jeweller’s wife as factual, which influenced the way the media reported on this case, as well as the reaction of the prosecutor, which was described as premature. Four dominant discursive patterns were detected, that is: normalizing the act, evaluating the act, upgrading the act and anticipating on the consequences of the act. Furthermore, it is demonstrated how critical tweets, displaying a concern for nuancing the overall tendency of the tweets, were designed in a way that downplayed their overt critical character. Implications of the analysis for crisis communication professionals are discussed. In deze studie wordt geruchtvorming in kaart gebracht met behulp van discursieve psychologie, waarin psychologische concepten zoals identiteit worden behandeld als discursieve constructies. De casus betreft een juwelenrook in Deurne, Nederland, waarbij de vrouw van de juwelier ervan beschuldigd werd twee overvallers te hebben doodgeschoten. Deze beschuldiging werd als feit behandeld op sociale media, ook al was dit nog niet officieel bevestigd. Dit beïnvloedde zowel de nieuwsberichtgeving, als de reactie van de officier van justitie in de media. Vier dominante discursieve patronen werden ontdekt in de discussie over de vermeende daad: normaliseren, evalueren, upgraden en anticiperen op de gevolgen. Ook wordt gedemonstreerd hoe tweets die nuance aanbrengen in de discussie, voorzichtig worden geformuleerd, waardoor het kritische karakter ervan wordt geminimaliseerd. Implicaties voor professionals in risiscommunicatie worden besproken.
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