Using an interaction timeline to investigate factors related to shedder status.

A major factor that influences DNA transfer is the propensity of individuals to 'shed' DNA, commonly referred to as their 'shedder status'. In this work we provide a novel method to analyse and interrogate DNA transfer data from a largely uncontrolled study that tracks the movements and actions of a group of individuals over the course of an hour. By setting up a model that provides a simplistic description of the world, parameters within the model that represent properties of interest can be iteratively refined until the model can sufficiently describe a set of final DNA observations.

Mass spectrometry-based proteomics for source-level attribution after DNA extraction.

Biological traces recovered from crime scenes serve as vital evidence in forensic investigations. While DNA evidence is frequently used to address the sub-source level of the hierarchy of propositions, the biological source of the DNA can be highly probative at the source level. Current body fluid detection methods pose certain limitations, such as reports of false positive results from some of the presumptive and/or confirmatory tests in current use.

Air DNA forensics: Novel air collection method investigations for human DNA identification.

Modern techniques can generate highly discriminatory DNA profiles from minuscule biological samples, providing valuable information in criminal investigations and court proceedings. However, trace and touch DNA samples, due to their nature, often have lower success rates than other biological materials, such as blood. Further, forensically aware criminals can utilize gloves and meticulously clean the crime scene to remove DNA traces of themselves from contacted surfaces.

How to best assess shedder status: a comparison of popular shedder tests.

"Shedder status" describes the inherent variation between individuals to leave touch DNA on a surface through direct contact. Depending on the amount and quality of DNA or cellular deposition, individuals are typically deemed high, intermediate, or low shedders. Although many shedder tests have been described, variability in study design and categorisation criteria has limited the ability of researchers to accurately compare results, as well as accrue the necessary population data.

Classification of epidermal, buccal, penile and vaginal epithelial cells using morphological characteristics measured by imaging flow cytometry.

As a result of the increased sensitivity of forensic DNA techniques, which can generate informative results from as little as a few cells, developing an understanding of the anatomical region these cells originate from is becoming more pertinent. Imaging Flow Cytometry (IFC) represents a promising method for identifying epithelial cells from different anatomical regions. This project aimed to determine whether IFC could be used to distinguish epithelial cells collected from different forensically relevant anatomical regions based on their morphology and autofluorescence.