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. Given its crucial role in forensic investigation, CSI decision-making must be further studied to understand how differences may arise during the stages of a crime scene investigation. The following exploratory research project is a first step at comparing how crime scene investigations of violent robberies are conducted between 25 crime scene investigators from nine countries across the world.Through a mock crime scene and semi-structured interview, we observed that CSIs have adopted a variety of investigation approaches. The results show that CSIs have different working strategies and make different decisions when it comes to the construction of relevant hypotheses, their search strategy, and the collection of traces. These different decisions may, amongst other factors, be due to the use of prior information, a CSI’s knowledge and experience, and the perceived goal of their investigation. We suggest the development of more practical guidelines to aid CSIs through a hypothetico-deductive reasoning process, where (a) CSIs are supported in the correct use of contextual information, (b) outside knowledge and expertise are integrated into this process, and (c) CSIs are guided in the evaluation of the utility of their traces.
This meta-analysis investigated the long term effects of prevention programs conducted during early and middle childhood on criminal offending during adulthood. The analyses included 3611 participants in 9 programs. The effect size for adult criminal offending was significant, but small in magnitude (OR=1.26; 95% CI=1.06-1.50, p=.011). The effects of the programs on positive outcomes (academic attainment and involvement in productive activity, such as being engaged in school or work) were somewhat larger and more consistent than effects on crime (OR=1.36, 95% CI=1.20-1.55, p<.001). Several participant and program characteristics moderated the effectiveness of (early) prevention. Children who were more at-risk and those from a lower SES benefited more. Shorter, but more intensive programs, and programs that focus on social and behavioral skills, rather than on academic skills or family support, tend to produce larger effects. Taken together, these results indicate that early prevention programs can help put children on a more positive developmental trajectory that is maintained into adulthood, but there is still no convincing evidence that they can prevent adult crime. Implications of the findings for research, policy and clinical practice are discussed.
Technological innovations enable rapid DNA analysis implementation possibilities. Concordantly, rapid DNA devices are being used in practice. However, the effects of implementing rapid DNA technologies in the crime scene investigation procedure have only been evaluated to a limited extent. In this study a field experiment was set up comparing 47 real crime scene cases following a rapid DNA analysis procedure outside of the laboratory (decentral), with 50 cases following the regular DNA analysis procedure at the forensic laboratory. The impact on duration of the investigative process, and on the quality of the analyzed trace results (97 blood and 38 saliva traces) was measured. The results of the study show that the duration of the investigation process has been significantly reduced in cases where the decentral rapid DNA procedure was deployed, compared to cases where the regular procedure was used. Most of the delay in the regular process lies in the procedural steps during the police investigation, not in the DNA analysis, which highlights the importance of an effective work process and having sufficient capacity available. This study also shows that rapid DNA techniques are less sensitive than regular DNA analysis equipment. The device used in this study was only to a limited extent suitable for the analysis of saliva traces secured at the crime scene and can mainly be used for the analysis of visible blood traces with an expected high DNA quantity of a single donor.
Nadat er een misdrijf heeft plaatsgevonden, doen forensisch onderzoekers van de Nationale Politie ter plekke onderzoek naar de toedracht van het incident. Hiertoe wordt gezocht en onderzoek verricht naar sporen op de plaats delict die aanwijzingen of antwoorden kunnen geven op de vragen: Wat is er gebeurd, hoe, en wie is hier verantwoordelijk voor? In dit onderzoeksvoorstel, DaVinciQD 2.0, gaan we onderzoek doen naar het dateren van biologische sporen, meer specifiek vingerafdrukken en bloedspatten. Voor forensisch onderzoek is het relevant om te bepalen of een aangetroffen vingerafdruk of bloedspoor afkomstig is van de dader. Maar het beantwoorden van de wie/wat vraag is in veel gevallen niet voldoende. Wat als de verdachte verklaart aanwezig te zijn geweest op de plaats-delict, maar niet ten tijde van het misdrijf, bijvoorbeeld omdat deze persoon daar woont of werkt? In dat geval wil je een antwoord op de hoe en wanneer-vraag: Wanneer is dit spoor aangebracht? Daarom is er vanuit de praktijk de dringende vraag naar een dateringsmethode die op de plaats-delict kan bepalen hoe oud een gevonden spoor is. HIermee wordt snel een antwoord verkregen, waarmee het forensische onderzoeksproces sneller en efficiënter kan worden uitgevoerd. De onderzoeksgroepen Applied Nanotechnology en Technologies for Criminal Investigations van Hogeschool Saxion, het Nederlands Forensisch Instituut, de Nationale Politie, Universiteit Twente, TU Delft en enkele private bedrijven willen gezamenlijk een methode ontwikkelen om met behulp van quantum dots de datering van biologische sporen op de plaats-delict mogelijk te maken. Deze nanometer-grote quantum dots zullen zodanig gefunctionaliseerd worden dat zij specifiek aan eiwitten in het spoor kunnen binden, om zo door middel van aanstralen met forensisch licht datering mogelijk te maken. De methode zal allereerst ontwikkeld en getest worden in het lab, om daarna ook in de praktijk van de forensische onderzoeker getest, gevalideerd en uitgeleerd te worden.
