A diagnostic program for estimating the time of death using microcalculators MK-61 and B3-34

The programme design is based on the process of changes in dead body temperature. Specific features of the process of changes in temperature values of a dead body are characterized by a parameter which involves process sample obtained by temperature measurements in diagnostical area of a cadaver at the accident scene during 1 hour. Programme provides for estimation of postmortem interval within the first 60 h after death occurrence. Diagnostical deviations don't exceed +/- 3% as compared to the real time of death.     

Evaluation of the Forensic Utility of Scanning Electron Microscopy‐Energy Dispersive Spectroscopy and Laser Ablation‐Inductively Coupled Plasma‐Mass Spectrometry for Printing Ink Examinations

Improvements in printing technology have exacerbated the problem of document counterfeiting, prompting the need for analytical techniques that better characterize inks for forensic analysis and comparisons. In this study, 319 printing inks (toner, inkjet, offset, and Intaglio) were analyzed directly on the paper substrate using scanning electron microscopy‐energy dispersive spectroscopy (SEM‐EDS) and Laser Ablation‐Inductively Coupled Plasma‐Mass Spectrometry (LA‐ICP‐MS). As anticipated, the high sensitivity of LA‐ICP‐MS pairwise comparisons resulted in excellent discrimination (average of ~ 99.6%) between different ink samples from each of the four ink types and almost 100% correct associations between ink samples known to originate from the same source. SEM‐EDS analysis also resulted in very good discrimination for different toner and intaglio inks (>97%) and 100% correct association for samples from the same source. SEM‐EDS provided complementary information to LA‐ICP‐MS for certain ink types but showed limited utility for the discrimination of inkjet and offset inks.     

Forensic Analysis of Explosives Using Isotope Ratio Mass Spectrometry (IRMS)—Part 1: Instrument Validation of the DELTAplusXP IRMS for Bulk Nitrogen Isotope Ratio Measurements

Abstract: A significant amount of research has been conducted into the use of stable isotopes to assist in determining the origin of various materials. The research conducted in the forensic field shows the potential of isotope ratio mass spectrometry (IRMS) to provide a level of discrimination not achievable utilizing traditional forensic techniques. Despite the research there have been few, if any, publications addressing the validation and measurement uncertainty of the technique for forensic applications. This study, the first in a planned series, presents validation data for the measurement of bulk nitrogen isotope ratios in ammonium nitrate (AN) using the DELTA^plusXP (Thermo Finnigan) IRMS instrument equipped with a ConFlo III interface and FlashEA? 1112 elemental analyzer (EA). Appropriate laboratory standards, analytical methods and correction calculations were developed and evaluated. A validation protocol was developed in line with the guidelines provided by the National Association of Testing Authorities, Australia (NATA). Performance characteristics including: accuracy, precision/repeatability, reproducibility/ruggedness, robustness, linear range, and measurement uncertainty were evaluated for the measurement of nitrogen isotope ratios in AN. AN (99.5%) and ammonium thiocyanate (99.99+%) were determined to be the most suitable laboratory standards and were calibrated against international standards (certified reference materials). All performance characteristics were within an acceptable range when potential uncertainties, including the manufacturer’s uncertainty of the technique and standards, were taken into account. The experiments described in this article could be used as a model for validation of other instruments for similar purposes. Later studies in this series will address the more general issue of demonstrating that the IRMS technique is scientifically sound and fit‐for‐purpose in the forensic explosives analysis field.