Forensic science experts develop new insights into crime scene analysis

Individuals deposit skin cells and DNA in different ways, but recent research from Flinders University suggests that certain people have stronger intra-variability in their cell deposits.

Forensic science experts at Flinders University are developing a set of new insights into crime scene investigation, including the distinction between high, intermediate, and low skin “shedders,” which will aid comprehension of trace or “touch DNA.”

The most recent study investigates the inter-variation of DNA shedding found in studies on materials collected from ten different persons and 30 of their thumbprints. It was published in the journal Forensic Science International: Genetics.

The first challenge at a scene is finding touch DNA, which is why we have developed an accurate special aerosol fluorescent dye ‘marker’. A further challenge is evaluating the value of the evidence, and that’s where shedders are a factor. Data like this new study allows a growing understanding of differences in DNA ‘shedding’ between people, and why we might find traces of people’s DNA a long time after an event.”

Professor Adrian Linacre, Forensic DNA Technology Research Group, Flinders University

Todd Kaesler, a biological forensics researcher at Flinders University noted, “We have found that some people have higher intra-variability, indicating that these individuals will not always reliably pass on similar amounts of cellular material and DNA. This is individual-dependent. Any new data on cell deposition goes to strengthen our understanding of how cells are deposited and why some are found well after a criminal event.”

The researchers utilized a nucleic acid binding dye to indicate how many cells are deposited when a person touches the object.

Our work leads to more reliable touch DNA collection methods, which can be key in forensic casework. We look forward to producing more accurate methods and informative research to help forensic scientists to fulfill their roles in a challenging environment.”

Professor Adrian Linacre, Forensic DNA Technology Research Group, Flinders University