National Commission on Forensic Science Federal Advisory Committee Meeting WebCast

Join the National Commission on Forensic Science Federal Advisory Committee Meeting 13 on April 10-11, 2017 in Washington, DC, or join via webcast.

The Committee will discuss the draft work product, “Views on Statistical Statements in Forensic Testimony; Views on Report and Case Record Contents.” We invite the greater forensics community to join us in reviewing the draft product, and to further enhance the practice and reliability of forensic science.

Register to attend or get the livestream link

Applied Research, Development, and Method Validation for a Statistically Based Comparison of Tool Marks using GelSight-Based Three Dimensional Imaging and Novel Comparison Algorithms for Firearm Forensics

Author: Ryan Lilien

Abstract:

TopMatch technology shows excellent and continually improving match accuracy; however, in order to fully establish the base credibility of the platform, it was necessary to establish best-scamming practices and to demonstrate that the method meets the quality-control criteria of other forensic instruments.

The current project aimed to enhance TopMatch by establishing best practices and conducting a set of methodology studies. The project followed the intent of the Scientific Working Group on DNA Analysis Methods’ Validation Guidelines for Analysis Methods document. That document describes seven validation criteria for new scientific methods: Accuracy, Stability, Precision, Repeatability, Reproducibility, Contamination Risk, and Performance Checks.

The current project complements the previous studies on "Accuracy" and evidence "Stability" by addressing the remaining issues of Precision, Repeatability, Reproducibility, Contamination Risk, and Performance Checks. In addition, researchers will study the effects of Cleaning Protocols, Focus Variation, and Ambient Lighting Variation.

Read the full Report

Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Laser Induced Breakdown Spectroscopy (LIBS) Analyses of Paper, Inks, and Soils

Author: Jose Almirall

Abstract: 

The commercial LIBS instrumental results were compared to previously optimized in-house LIBS systems and also to the alternative forensic tools of LA-ICP-MS, mXRF, and SEM-EDS, which offer good analytical performance but suffer from either very high costs and significant complexity (in the case of LS-ICP-MS) or analytical limitations in the form of sample requirement and relatively high detection limits (in the case of mXRF and SEM-EDS).

Although less mature than LA-ICP-MS, LIBS also shares the benefits associated with laser ablation methods, with the added advantage of improved speed, versatility, ease of operation, affordability, and portability.

This project shows that both LA-ICP-MS and LIBS are useful analytical tools for the analysis of paper, inks, soil, and cotton. The results have been presented in analytical chemistry and forensic science journals and venues.

Read the full report