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This study determined that the detection of spermatozoa could be improved by submitting sexual assault swabs directly for Differential Lysis extraction, whilst preserving the ability to conduct presumptive testing, eliminating the need to prepare a microscopic slide during initial examination. Analysis of semen from cotton swabs, rayon swabs, scrapings, tape-lifting and excisions from both thick and thin fabrics was conducted to ensure that the methodologies evaluated were tested on a range of exhibits and biological fluids typically seen in routine forensic casework. Results showed that microscopy slides created during Differential Lysis Extraction performed favourably in comparison with slides created during initial examination. A newly developed sexual assault process gave comparable detection levels to the traditional processing for Prostate Specific Antigen (p30) and Phadebas presumptive testing. It should be noted that the detection sensitivity for Acid Phosphatase (AP) was slightly better for traditional processing. The sensitivity of p30 was shown to be far superior to that of AP across most experiments. [ABSTRACT FROM AUTHOR]

This research was designed to assess the operational effectiveness of Biogeographical Ancestry (BGA) and Externally Visible Characteristics (EVCs) Massively Parallel Sequencing (MPS) for criminal cases. Engaging with end users to assess new DNA technology is a novel approach for Queensland, and considered necessary given the investment required to develop this capability. Detectives were presented with MPS intelligence from four real Queensland criminal cases in a workshop setting, and were asked to assess its utility. Detectives were also asked to determine whether they could use the MPS intelligence to prioritize (include/exclude) persons of interest (POIs). The results from this research showed the detectives had confidence in MPS intelligence and its value in providing avenues for investigation. There was a high rate of correct interpretation and use of the MPS results; however, the frequency of errors suggest that detectives need support from a trained forensic biologist to ensure accurate result interpretation. Detectives excluded on average 30% of POIs, demonstrating the potential use of MPS intelligence to prioritize POIs. Although this workshop did not accurately replicate an active criminal investigation, the results of this research are encouraging and suggest that MPS intelligence is operationally effective and could be used in Queensland as a valuable investigative tool. [ABSTRACT FROM AUTHOR]

There is a desire in the forensic science community for a robust tool for detecting trace DNA at the crime scene or on collected evidence. Recent research supports the fluorescent DNA-binding dye Diamond Dye (DD) as potentially effective for this purpose. However, additional research is required into the use of DD on trace DNA samples collected from mock evidence (e.g. clothing) to establish its practicality in an operational setting. Most importantly, any tool for detecting trace DNA must have no negative impact on downstream processes and must produce a reliable signal of presence/absence of DNA. Therefore, we aimed to determine whether DD staining of tapelifts taken from mock clothing exhibits impacts DNA yield and STR profiling success, and whether observed fluorescence on stained tapelifts corresponded with DNA yield. Using a paired sample approach of stained/unstained tapelifts from the same item, our results suggest that DD-stained tapelift samples generally recovered less DNA than unstained tapelifts, which resulted in poorer STR profiling success. Further, there was no association between the degree of fluorescence observed for stained tapelifts and DNA yield or STR profiling success. Taken together, these results suggest that DD staining may not be suitable for detecting trace DNA on tapelifts. [ABSTRACT FROM AUTHOR]