An interlaboratory study evaluating the interpretation of forensic glass evidence using refractive index measurements and elemental composition.

Seventeen laboratories participated in three interlaboratory exercises to assess the performance of refractive index, micro X-ray Fluorescence Spectroscopy (μXRF), and Laser Induced Breakdown Spectroscopy (LIBS) data for the forensic comparison of glass samples. Glass fragments from automotive windshields were distributed to the participating labs as blind samples and participants were asked to compare the glass samples (known vs. questioned) and report their findings as they would in casework.

Development of a method for the elemental analysis of milk powders using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and its potential use in geographic sourcing.

Milk has been reported as one of the most adulterated foodstuffs in the developed and developing world. One way to detect adulteration is to determine whether the country of origin on the label could be the actual country of origin. Such profiling may be accomplished through the use of elemental analysis techniques, however this is a preliminary study and this goal is not yet met.

The use of LA-ICP-MS databases to calculate likelihood ratios for the forensic analysis of glass evidence.

Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) has been shown to be an excellent technique for the discrimination of glass originating from different sources and for the association of glass originating from the same source. Typically, a match criterion is used to compare the elemental profile of the known sample to a questioned sample and if the glass samples are determined to "match" this may be followed by the use of a verbal scale to report the forensic practitioner's conclusion. This approach has several disadvantages: a fixed match criterion suffers from the "fall-off-the-cliff effect," the rarity of an elemental profile is not taken into account, and the use of a verbal scale to assign a weight of evidence may be considered as subjective and can vary by examiner.