The Bayesian approach to reporting GSR analysis results: some first-hand experiences

Charles, Sébastien; Nys, Bart

doi:10.1117/12.853446

Cited by 1 publication

(2 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The interplay between particle and pixel sizes is a fundamental statistical aspect that the authors believe has not been discussed quantitatively in the literature. Bayesian methods are the appropriate standpoint to address this problem and are a growing technique in the forensic field, specifically in GSR analysis as pointed out by [14]. We refer the reader to the pioneering work of [15, 16] for an introduction to the use of Bayesian statistics in forensic sciences.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

False‐negative probability in the SEM/EDS automated discovery of iGSR particles: A Bayesian approach

Onetto

Edgardo²,

Pregliasco

2023

Journal of Forensic Sciences

View full text Add to dashboard Cite

The automated search software integrated with a scanning electron microscope (SEM/EDS) has been the standard tool for detecting inorganic gunshot residues (iGSR) for several decades. The detection of these particles depends on various factors such as collection, preservation, contamination with organic matter, and the method for sample analysis. This article focuses on the influence of equipment resolution setup on the backscattered electron images of the sample. The pixel size of these images plays a crucial role in determining the detectability of iGSR particles, especially those with sizes close to the pixel size. In this study, we calculated the probability of missing all characteristic iGSR particles in a sample using an SEM/EDS automated search and how it depends on the image pixel resolution setup. We developed and validated an iGSR particle detection model that links particle size with equipment registers and applied it to 320 samples analyzed by a forensic science laboratory. Our results show that the probability of missing all characteristic iGSR particles due to their size is below 5% for pixel sizes below 0.32 μm2. These findings indicate that pixel sizes as large as twice the one commonly used in laboratory casework, that is, 0.16 μm2, are effective for initial sample scanning, yielding good detection rates of characteristic particles that could exponentially reduce laboratory workload.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Bayesian methods are the appropriate standpoint to address this problem and are a growing technique in the forensic field, specifically in GSR analysis as pointed out by [14]. We refer the reader to the pioneering work of [15,16] for an introduction to the use of Bayesian statistics in forensic sciences.…”

Section: Introductionmentioning

confidence: 99%