Scene of death investigation in apparent suicidal deaths in Rotterdam, the Netherlands.

Guidelines from the Netherlands describe that unnatural deaths should be investigated by a forensic physician and Crime Scene Technicians, but this is not always the case. In this study, we aimed to determine what predicts the non-attendance of the Crime Scene Technicians at the scene of the death of suicides in the police region in Rotterdam, the Netherlands. Data of 315 suicides (2016-2017) that have been externally examined by forensic physicians and reports from the Crime Scene Technicians were analysed. Statistical analysis was performed to determine the factors predicting the involvement of the Crime Scene Technicians at the scene of death. The Crime Scene Technicians were not attending in 23% (n = 72) cases, and over half of these cases were not found in the registration system of the Crime Scene Technicians. About some the Crime Scene Technicians was not informed. Predictors of the non-attendance of the Crime Scene Technicians were suicide by poisoning, the individual was found by an acquaintance or family, a history of suicide attempts and examination of the deceased in the hospital. In this study, we observed that the Crime Scene Technicians were sometimes not attending the investigation of apparent suicides. More research on this topic should be done to investigate the value of the presence of the Crime Scene Technicians at the scene before concluding that non-attendance of Crime Scene Technicians on-site influences the quality of the scene of death investigation and corresponding conclusions. Since 2017, several quality improvements were made, but an (inter)national conjoint protocol for uniform and structural suicide investigation could secure the quality of the scene of death investigation of suicides and would provide information useful for evaluation.

Forensic soil provenancing in an urban/suburban setting: A simultaneous multivariate approach.

Soil is a ubiquitous material at the Earth's surface with potential to be a useful evidence class in forensic and intelligence applications. Compositional data from a soil survey over North Canberra, Australian Capital Territory, are used to develop and test an empirical soil provenancing method. Mineralogical data from Fourier Transform InfraRed spectroscopy (FTIR) and geochemical data from X-Ray Fluorescence (XRF; for total major oxides) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS; for both total and aqua regia-soluble trace elements) are obtained from the survey's 268 topsoil samples (0-5 cm depth; 1 sample per km2 ). The simultaneous provenancing approach is underpinned by (i) the calculation of Spearman's correlation coefficients (rS ) between an evidentiary sample and all the samples in the database for all variables generated by each analytical method; and (ii) the preparation of an interpolated raster grid of rS for each evidentiary sample and method resulting in a series of provenance rasters ("heat maps"). The simultaneous provenancing method is tested on the North Canberra soil survey with three "blind" samples representing simulated evidentiary samples. Performance metrics of precision and accuracy indicate that the FTIR (mineralogy) and XRF (geochemistry) analytical methods offer the most precise and accurate provenance predictions. Maximizing the number of analytes/analytical techniques is advantageous in soil provenancing. Despite acknowledged limitations, it is concluded that the empirical soil provenancing approach can play an important role in forensic and intelligence applications.

Forensic soil provenancing in an urban/suburban setting: A sequential multivariate approach.

Compositional data from a soil survey over North Canberra, Australian Capital Territory, are used to develop and test an empirical soil provenancing method. Mineralogical data from Fourier transform infrared spectroscopy (FTIR) and magnetic susceptibility (MS), and geochemical data from X-ray fluorescence (XRF; for total major oxides) and inductively coupled plasma-mass spectrometry (ICP-MS; for both total and aqua regia-soluble trace elements) are performed on the survey's 268 topsoil samples (0-5 cm depth; 1 sample per km2 ). Principal components (PCs) are calculated after imputation of censored data and centered log-ratio transformation. The sequential provenancing approach is underpinned by (i) the preparation of interpolated raster grids of the soil properties (including PCs); (ii) the explicit quantification and propagation of uncertainty; (iii) the intersection of the soil property rasters with the values of the evidentiary sample (± uncertainty); and (iv) the computation of cumulative provenance rasters ("heat maps") for the various analytical techniques. The sequential provenancing method is tested on the North Canberra soil survey with three "blind" samples representing simulated evidentiary samples. Performance metrics of precision and accuracy indicate that the FTIR and MS (mineralogy), as well as XRF and total ICP-MS (geochemistry) analytical methods, offer the most precise and accurate provenance predictions. Inclusion of PCs in provenancing adds marginally to the performance. Maximizing the number of analytes/analytical techniques is advantageous in soil provenancing. Despite acknowledged limitations and gaps, it is concluded that the empirical soil provenancing approach can play an important role in forensic and intelligence applications.