DNA and Body Fluid Analysis

Laura Walton, lecturer in Forensic Science, leads the department’s research into DNA and body fluid analysis.

Her research is focused on several key areas including:

• Transfer of DNA

• Persistence of DNA

• Interpretation of mixed and partial DNA profiles

• DNA recovery from evidential items

Due to an enduring culture of gun related crime, both in the UK and on an international level, the ability to positively identify the individual who handled or discharged a weapon has remained important. Although fingerprints are an ideal form of identification, the ability to develop identifiable fingerprints on spent cartridge cases is variable.  Factors such as the type of weapon, the type of cartridge case and the calibre all influence the success of enhancing fingerprints.  Other methods of identifying the handler of the cartridge case, in the form of a DNA profile or sequence, would offer a useful alternative. This project initially identified the factors that affect the potential for retrieving a DNA profile from a spent cartridge case, determined whether those factors could be addressed and explored a variety of mechanisms for improving the quality of the DNA recovered.

Walton, L.M, Jackson, AJ and Mountain HM. (2011) Poster presentation entitled ‘The Retrieval of a DNA profile from Spent Cartridge Cases’ at the International Forensic Science Conference, University of Technology, Jamaica.  To view a copy of the research presented please click here (PDF, file size: 49.57KB) .

If a DNA profile can be recovered from an evidential item, it is important to be able to state with confidence that the presence of an individuals DNA profile indicates that he/she was the final person to handle that object.  It is also important to be able to ensure that the reason that persons DNA profile is present is because they handled the evidential item itself, and not due to transfer from another person or object (whether that transfer be deliberate or incidental).  This research involved studying the persistence and transfer of DNA to examine if the DNA profile found on an object is indicative of the final person to handle that object, and also to determine the potential for an individual to transfer another persons' DNA onto that object.  The variables influencing secondary transfer of DNA have been identified and tested to determine which factors could be prioritised.

Walton, L.M, Jackson, AJ and Mountain HM. (2011) Poster presentation entitled ‘The Secondary Transfer of DNA: The Influence of Shedder Status on the Dominant Donor in a Mixed Profile’ at the Forensic Science Society DNA Conference and Body Fluids Forum, Manchester.  To view a copy of the research presented please click here (PDF, file size: 49.91KB) .

Dr Harry Mountain and Laura Walton are also supervising a PhD student, Charlotte Orphanou, whose research is centered on the age determination of body fluids.  For more information on the research undertaken by Charlotte Orphanou please click here (PDF, file size: 28.18KB) .

For more information please visit Laura Walton’s Staff Profile Page.