Comparison of forensic glass analysis by LA-ICP/MS with XRF and sem-EDS

All information obtained from the crime scene is critical for the proper conduct of the forensic investigation and the subsequent court process. Analyzing all the collected evidence with the correct analysis method, determining the statistical significance of the data obtained and comparing it with appropriate databases, if available, is critical in analyzing the incident. Glass, which is classified as material evidence, is important evidence in many respects. When broken or shattered, glass breaks into many small particles and can be transferred to secondary crime scenes on the victim's or perpetrator's clothing, hair, and belongings. These small glass fragments, which can also be obtained in cases such as hit-and-run or robbery, are also important in terms of providing a connection with the primary crime scene. Physical and chemical examinations on the glass fragments obtained from the crime scene also help to obtain information about what kind of glass it is. In this study, 57 glass samples from 3 different groups (bottle, float glass and headlamp) were chemically analyzed with 3 different techniques which are, LA-ICP-MS, XRF and SEM-EDS. Hierarchical Clustering Analysis (HCA) and Principal Component Analysis (PCA) methods, which are widely used in chemometric studies, were used to classify the glass samples. As a result of the experimental analyses, it was seen that a reliable identification and differentiation of glass samples can be made by evaluating more than one element together rather than differentiation based on a single element. In addition, as a result of the statistical method evaluation, it was seen that the class distinction between glass samples could be made with a higher score when 3-dimensional principal component analysis was applied.