DNA detection of a temporary and original user of an office space

Mariya Goray; Bas Kokshoorn; Kristy Steensma; Bianca Szkuta; Roland A H van Oorschot

doi:10.1016/j.fsigen.2019.102203

DNA detection of a temporary and original user of an office space

Forensic Sci Int Genet. 2020 Jan:44:102203. doi: 10.1016/j.fsigen.2019.102203. Epub 2019 Nov 11.

Authors

Mariya Goray¹, Bas Kokshoorn², Kristy Steensma², Bianca Szkuta³, Roland A H van Oorschot⁴

Affiliations

¹ Biometric Division, Victoria Police Forensic Services Department, Macleod, Australia. Electronic address: mariya.goray@police.vic.gov.au.
² Division Biological Traces, Netherlands Forensic Institute, The Hague, the Netherlands.
³ Office of the Chief Forensic Scientist, Victoria Police Forensic Services Department, Macleod, Australia; School of Life and Environmental Sciences, Deakin University, Geelong, Australia.
⁴ Office of the Chief Forensic Scientist, Victoria Police Forensic Services Department, Macleod, Australia; School of Molecular Sciences, College of Science, Health and Engineering, La Trobe University, Bundoora, Australia.

PMID: 31751912
DOI: 10.1016/j.fsigen.2019.102203

Abstract

There is a need to improve our awareness of the transfer, persistence, prevalence and recovery of DNA (DNA-TPPR) from items/surfaces, and within different spaces and circumstances, to assist sample targeting during collection and activity level assessments. Here we investigate DNA-TPPR within office spaces. Specifically, to what extent DNA, left by a temporary user of an office space that has been occupied by a regular user for an extended period, is detectable when the duration of their temporary occupancy and their general activities are known. Also, how readily the DNA of the regular user is still detectable after a known period of occupancy by another person, and to what extent DNA of others is present. Samples were collected from 18 core items/surfaces within eight single use office spaces that had been used temporarily by another occupant for 2.5-7 h. Four of these offices were within one forensic laboratory and four within another. Each lab collected and processed the samples to generate DNA profiles using their own set of methodologies. The owner/regular user of an office space was found to be the major/majority contributor to profiles from most items within the space, even after temporary use by another person. The detectability of the temporary occupier of an office space varied among offices and items. The temporary occupier was not observed on all items touched. In most instances, when detected, the temporary occupier was known to have touched the surface at some stage. Therefore, where one is seeking to collect samples that may detect a temporary user of a space, it is advisable to target several potentially touched sites. A difference in methodologies applied from collection through to profiling appears to impact DNA yields and profile types. Ascertaining the impact of using different methodologies on the profiles generated from collected samples, requires further research. More research is also needed to generate data to help determine frequency estimates for different types of profiles given different user histories of an item or space.

Keywords: Activity level; DNA persistence; DNA prevalence; DNA recovery; DNA transfer; Trace DNA.

MeSH terms

DNA / analysis*
DNA Fingerprinting*
Humans
Microsatellite Repeats
Polymerase Chain Reaction
Software
Specimen Handling / methods
Touch*

Substances

DNA