Forensic Science International: Synergy最新文献

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 (C_llr) is a popular metric for such systems, penalizing misleading LRs further from 1 more. C_llr = 0 indicates perfection while C_llr = 1 indicates an uninformative system. However, beyond this, what constitutes a “good” C_llr is unclear.

Aiming to provide handles on when a C_llr is “good”, we studied 136 publications on (semi-)automated LR systems. Results show C_llr use heavily depends on the field, e.g., being absent in DNA analysis. Despite more publications on automated LR systems over time, the proportion reporting C_llr remains stable. Noticeably, C_llr values lack clear patterns and depend on the area, analysis and dataset.

As LR systems become more prevalent, comparing them becomes crucial. This is hampered by different studies using different datasets. We advocate using public benchmark datasets to advance the field.

No-body homicide cases are typically difficult to investigate, owing to the lack of forensics and leads. Researchers in the fields of forensics, criminology, and psychology have attempted to provide assistance to these investigations through their respective disciplines. The focus of the current case study review is on a combined approach to assisting in no-body homicides and cold cases. The proposed approach will outline a geographical profiling technique that has previously been used in no-body homicide investigations, Winthropping. Alongside this, forensic linguistic analyses will be outlined to show how a combination may provide fresh leads and investigative avenues for further exploration. A series of 4 real-world cases in which bodies were moved, dumped, and hidden by a suspect, who subsequently revealed knowledge of the clandestine grave are given. The aim is that readers from related fields and disciplines might synergistically collaborate to develop the area and further help in these cases.

The high value placed on forensic information in the criminal justice process is demonstrated by the fallout resulting when questions are raised as to the validity of methods used, deficiencies in the understanding of the limitations of results, or uncertainties around the professional expertise or ethical practices of the provider of the information. To effectively act as the “speaker” for the scientific evidence in court, forensic science needs to have credibility. The workshop “Rethinking scientific communication in courts” held at the Australian National University College of Law in November 2023 explored the subject of science communication in the legal context through the lens of philosophy, law, forensic service provision and meta-science, demonstrating the unique challenges placed on the field of forensic science as a scientific profession confined and defined within a non-scientific system. Stemming from the discussions at the workshop, this paper examines the notion of credibility in science, how forensic science aligns with the hallmarks of a credible scientific community and the influence this has on our understandings of scientific communication in courts.

Forensic laboratories face a multitude of challenges when striving to deliver services to the criminal justice system. While many of these issues change over time, one in particular seems to endure the test of time … the need for faster results. Law enforcement wants and needs quicker response times to access critical information required to investigate their cases. One answer to this persistent problem is evolving technology. Technology not only permits a much quicker response than forensic laboratories are currently delivering, it can open the door to solving previously unsolvable cases. Along with applying new technology, an evaluation of current forensic laboratory product lines, service delivery models, and mindset regarding the role of forensic science-based investigative leads (termed forensic leads) is warranted. Resources and strategic planning are needed to realize the full potential of evolving technologies and what forensic laboratories can do to provide actionable and timely forensic leads to our criminal justice partners as a normal course of action instead of as an exception.

This proposal is to establish a permanent, designated Forensic Lead Program (FLP) that resides under the umbrella of an accredited forensic laboratory and is tasked with the development and release of forensic leads. The FLP involves a focused menu of services, defined personnel roles, strict protocols, short turnaround time, standardized expectations, and targeted training, combined with the sense of urgency needed for consistent delivery of timely and actionable forensic leads. A dedicated FLP will save time and money by providing critical information for more focused investigations. ‘Speed is the need’ … for quick identification of those that threaten public safety and for the equally quick elimination of those wrongfully accused.

Programs at two large state forensic laboratories will demonstrate how these concepts could be implemented along with their learning experiences. A business case will also be included to demonstrate the cost benefit of the Forensic Lead Program for DNA (CODIS – Combined DNA Index System) and NIBIN (National Integrated Ballistic Information Network), however other section services are expected to see similar benefits. Improving the response time by one day saves $1677.75 per $1 spent [1]. The return on investment (ROI) for applying DNA to firearms evidence returns $47.88 per $1 spent, or an 4,788 % ROI. Applying NIBIN (National Integrated Ballistic Information Network) to firearms evidence to provide investigative leads is $502.19 per $1 spent, which is a 50,219 % ROI. Recasting the forensic laboratory product line and service delivery model to ‘Lead with Speed’ makes both economic and investigative sense.

Aim

Postmortem Computed Tomography (PMCT) is gradually introduced at forensic institutes. Image reconstruction software can increase diagnostic potential in CT by increasing distinction between structures and reduction of artifacts. The aim of this study was to develop and evaluate novel image reconstruction parameters for postmortem conditions, to increase image quality and diagnostic potential of CT scans.

Method

Twenty PMCT scans of deceased hereof two in severe decay were subjected to four reconstruction techniques: a standard reconstruction algorithm, the detail reconstruction algorithm and two novel algorithms based on the standard algorithm, but with different Hounsfield settings. Image quality was evaluated by visual grading analysis (VGA) by four forensic radiologist observers.

Results

The VGA did not prove that any of the reconstruction techniques were superior to the others. For standard and detail, the two pre-defined reconstruction algorithms, VGA scores were indiscernible and were superior to the equally indiscernible Hounsfield reconstructions on parameters translated into Sharpness and Low Contrast Resolution. The two alternative Hounsfield settings were superior with respect to Noise and Artifacts/Beam Hardening.

Conclusion

The study elucidates the possiblity for multiple reconstructions specialized for PMCT conditions, to accommodate the special conditions when working with the deceased. Despite the lack of clear improvements in the tested reconstructions, this study provides an insight into some of the possibilities of improving PMCT quality using reconstruction techniques.

Most of the forensic evidence evaluations given activity level propositions are centered around an item which is assumed to be linked to an alleged activity. However, the relation between an item of interest and an activity may be contested. This study presents a template Bayesian network (BN) for the evaluation of transfer evidence given activity level propositions considering a dispute about the relation of an item to one or more activities. The template BN includes a set of association propositions that enables the combined evaluation of evidence concerning alleged activities of the suspect and evidence concerning the use of an alleged item in those activities. Since the two types of evidence are often from different forensic disciplines, the BN is especially useful in interdisciplinary casework. Throughout the paper, we use a fictive case example that captures the essence of cases for which the template model can be used. The template BN provides a flexible starting point that can be adapted to specific case situations and supports structured probabilistic reasoning by a forensic scientist.