The American Society of
Crime Laboratory Directors

This presentation will examine the process of single cell and targeted cell analyses from a forensic perspective using select studies to highlight the methods, expected results, advantages/disadvantages and the transition of these analyses from research to the forensic laboratory. Collectively, these studies
demonstrate that single cell analysis can be successfully used and implemented in a forensic setting, providing significant advantages over current methods in many situations encountered in casework. Fluorescence-activated cell sorting (FACS) is a well-established technology often used in the clinical setting to enrich rare target cells from a mixed cell populations based on phenotypical characteristics detected by flow cytometry. To counter the shortcomings of differential lysis, a methodology has been established to sort sperm from epithelial cells by means of FACS in the context of sexual assault casework. A comparative study of both methods revealed an improved separation efficiency and a higher DNA profile quality for SpermFACS, making it a viable alternative to differential lysis. The first step in interpreting a collection of single cell signatures is to cluster them into groups by unknown genotype. With multifarious clustering approaches being available, one challenge is to ascertain what one to adopt. Using proper scoring rules, we introduce a framework that summarizes three key performance factors: Salience, Legitimacy and Credibility (SLC). With SLC analytics demarcating translation borders, we report in what attribute one system outperforms another and adopt the one that excels in the major SLC components.