Persistence and secondary transfer of DNA from previous users of equipment

Fonneløp, Ane Elida; Johannessen, Helen; Gill, Peter

doi:10.1016/j.fsigss.2015.09.077

Cited by 21 publications

(33 citation statements)

References 3 publications

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“…Detection of indirectly-transferred unknown DNA alongside expected DNA from the donor has been repeatedly reported, commonly at ≤10% of the profiles obtained, by studies involving handling or wearing of items and DNA profiling using the more sensitive kits [4,10,11,15,16,[25][26][27][28]. It is proposed that hands acquire such nondonor DNA via everyday activities that involve touching other people and other items that have been previously handled [10,16,20,27,28]. As such, the recovery of nondonor DNA from handled items is no longer an unexpected observation and should be considered a common feature of touch samples [28].…”

Section: Detection Of Indirectly-transferred Unknown Dnamentioning

confidence: 99%

“…More recently, indirectlytransferred DNA has been observed in mock social settings [4] and stabbing simulations [5], and has been a key consideration in several high profile criminal cases, such as R v Reed & Reed [6], Fitzgerald v The Queen [7] and the miscarriages of justice of Amanda Knox and Raffaele Sollecito [8]. Furthermore, given that DNA can persist on surfaces for a number of days or weeks depending on the environmental conditions [9] and on objects after use by a subsequent person [10][11][12], persistence of both directly and indirectly transferred DNA also needs to be considered in the evaluation of trace DNA in casework.…”

Section: Introductionmentioning

confidence: 99%

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Trace DNA evidence dynamics: An investigation into the deposition and persistence of directly- and indirectly-transferred DNA on regularly-used knives

Meakin¹,

Butcher²,

Oorschot

et al. 2017

Forensic Science International: Genetics

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Empirical data on the transfer and persistence of trace DNA are crucial to the evaluation of forensic DNA evidence. This evaluation can be complicated by the occurrence of indirect DNA transfer; the possibility of which is well established, but research into such transfer is often focussed on unrealistic situations, e.g. handling of DNA-free items after participants have shaken hands for 1-2min. To simulate more realistic scenarios, this study investigated the deposition and persistence of both directly- and indirectly-transferred DNA on knives that had been artificially set up as 'regularly-used'. Each knife was handled in a prescribed manner by a specific participant over two consecutive days to simulate regular use. Each participant then shook hands for 10s with a fellow volunteer and immediately stabbed one of their knives into a foam block repeatedly for 60s. DNA was recovered by mini-taping from triplicate sets of knife handles from four pairings of volunteers after regular use, and at one hour, one day and one week after the handshaking and stabbing events. Total amounts of DNA recovered from the knives, regularly used by a single person, varied among individuals; one volunteer consistently deposited significantly greater amounts than the others, whilst another volunteer did not always leave complete profiles. DNA attributed to the regular user persisted for at least a week, declining with increasing time between DNA deposition and recovery. Non-donor DNA was co-deposited at <5% of the profiles recovered, except for one volunteer, who consistently left DNA from their romantic partner on their knives at ∼25% and ∼11% of the profiles before and after the handshaking and stabbing events, respectively. In three pairings of volunteers, after the handshaking and stabbing events, alleles that could be attributed to the respective handshakers' profiles were detected as partial minor profiles, equating to ∼10% of the profiles recovered. For the fourth pairing of volunteers, only complete single-source DNA profiles matching the regular user's profile were recovered. However, it is important to note that, when indirectly-transferred handshaker DNA was detected, it declined with increasing time between DNA deposition and recovery. These data provide an initial insight into the detection and persistence of directly- and indirectly-transferred DNA that extend the data already available on forensic DNA transfer. The results herein suggest that the sooner an item is sampled after an offence has occurred, the greater the chance of recovering indirectly-transferred DNA, which has implications for forensic reconstructions.

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Section: Detection Of Indirectly-transferred Unknown Dnamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Trace DNA evidence dynamics: An investigation into the deposition and persistence of directly- and indirectly-transferred DNA on regularly-used knives

Meakin¹,

Butcher²,

Oorschot

et al. 2017

Forensic Science International: Genetics

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“…Here four volunteers had their keyboards and mouse swapped with another's with swabs taken from both objects and volunteers at the beginning and throughout the study. 49 Swabs taken before the study had begun showed DNA present from unknown individuals, but unfortunately it cannot be concluded if this DNA was secondarily transferred or through direct contact. The author's attributed this occurrence to background DNA being present on everyday objects.…”

Section: Indirect Findings Of Secondary Transfermentioning

confidence: 99%

Meta-analysis of the secondary transfer of DNA

Dunhill

Chapman

2019

Australian Journal of Forensic Sciences

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Deoxyribonucleic acid (DNA) is complex molecule present in nearly every cell of the human body that contains all of an individual's genetic material. Trace DNA has allowed DNA to be detected on everyday objects such as door handles, tables and chairs. Currently, the idea of the secondary transfer of DNA has arisen, involving the transfer of genetic profiles from an individual through a vector and then to final individual or object. This has become a reoccurring term in the court system, as individuals standing trial use this argument for the presence of their DNA. It is therefore hypothesized that through the exploration of literature and completion of a meta-analysis that an appropriate and concise guide will be produced to determine the chances of a secondary transfer event occurring and what conditions are required, to aid Biologists in expert testimony. Database searches were conducted to gain resources in the topic, followed by a number of screens to determine the suitability of articles for the meta-analysis. With the resultant 38 articles, data extraction was additionally carried. However, due to the lack of quantitative variables and results, a meta-analysis was not able to be conducted. It is suggested that in the future, studies publish their results in a more scientifically rigorous manner or allow the access of raw results for external interpretation purposes. TABLE OF CONTENTS ABSTRACT……………………………………………………………………………………………………………………. LIST OF ABBREVIATIONS……………………………………………………………………………………………….

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“…Other studies examining the transfer of "touch" DNA in less controlled scenarios, considered more realistic examples of secondary transfer rates, have observed the transferred DNA as the major or only component to the profile on far fewer occasions, if at all:~2.8% in studies where the source of the transferred DNA was known (9-12);~1.4% in studies where the source of the transferred DNA was unknown (13,14). Several other studies allude to the detection of secondarily transferred DNA from known and/or unknown sources within the samples obtained, but provide insufficient information with respect to their presence forming a minor or major component of the profile, and in the case of foreign alleles, whether they originated from a single or multiple sources (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26).…”

Section: Sirmentioning

confidence: 99%

“…Further, Cale et al (1) posit that the transfer of DNA through an intermediary has not been systematically evaluated with current technology. Studies have provided empirical evidence of secondary (and further, including tertiary and quaternary) transfer (9,10,16,27), have investigated variables that may affect the transfer and subsequent detection of touch DNA (7,8,13,18,20,(22)(23)(24)28,29), have provided casework relevant examples and simulations to model the possible effect of transfer on conclusions (9)(10)(11)14,16,17,21,(30)(31)(32), and have provided statistical models to evaluate the possibility of transfer (33)(34)(35). Such studies have been conducted with various autosomal STR methods employed in forensic biology, including the current sensitive technologies, and, more recently, with alternate methods such as mRNA profiling (18,21).…”

Section: Sirmentioning

confidence: 99%