Assessing trace DNA evidence from a residential burglary: Abundance, transfer and persistence

doi:10.1016/j.fsigss.2007.10.040

Forensic Science International: Genetics Supplement Series

Volume 1, Issue 1, August 2008, Pages 442-443

https://doi.org/10.1016/j.fsigss.2007.10.040 Get rights and content

Abstract

The considerable identifying power of DNA can see it treated as an absolute form of evidence, rather than as any other trace evidence. This study aimed to provide data into the abundance, transfer and persistence of trace DNA, in a particular crime scenario—residential burglary. Background levels of DNA on common burglary entry points were found to be low, however transfer of DNA during the action of a break-in is also low. The ability to recover analyzable DNA from outdoor surfaces decreases rapidly over several weeks.

Introduction

DNA has played a role in forensic investigations in only the last 20 years. The technology has progressed considerably in that time, however the interpretative framework on which this evidence is based has been somewhat neglected. Having data to give estimates on the properties of DNA as physical evidence will enable investigators and scientists to assess its value as evidence in a particular case. Combining the particular case circumstances with experimental data on these properties will provide a more grounded, Bayesian-type interpretation of a trace DNA profile.

The specific crime type of residential burglary was investigated in this study, and the trace evidence characteristics of abundance, transfer and persistence of DNA were tested.

Section snippets

Abundance study

This study aimed to determine the baseline level of trace DNA present at common entry points of residential burglary. Twenty-nine volunteer residences were selected in inner Sydney. Prior to the experiment, a survey of 100 burglaries was conducted to determine the most common entry points. From this survey, four to five areas (windows, doors) in each residence were swabbed using a double swab method.

The swabs were extracted using a standard chelex method. Swab extracts were amplified using a

Conclusion

This research demonstrates trace evidence characteristics of DNA, being abundance, transfer and persistence, in the context of residential burglary. Providing data into the many variables involved in trace DNA analysis allows a more objective probabilistic approach to the interpretation of profiles, and assists the presentation of this evidence in court.

Conflict of interest

None.

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Citation Excerpt :
This is crucial when there are legitimate reasons that could lead to the presence of the DNA of a given person of interest on an object or a person. This situation can be encountered with DNA collected on burglary scenes, as the quantity of DNA transferred and recovered because of these activities will generally be low [11]. In this article, we discuss a case where DNA is recovered from a door handle of a burgled house.
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Research articleAssessing trace DNA evidence from a residential burglary: Abundance, transfer and persistence