- •Progressive increase of the second user’s DNA contribution, relative to the first user, was observed over time in 218 out of 234 (93%) simulated traces.
- •Single-source DNA profile was shown to represent only 3 out of 234 (1%) traces simulated on objects touched by two users.
- •Partial/full DNA profiles of known participants were indirectly transferred in 9 cases (4%).
- •Apart from 1 case out of 234, indirectly transferred DNA represented the minor fraction of the mixed DNA profiles observed.
Traces collected on crime scene objects frequently result in challenging DNA mixtures from several contributors in different DNA proportions. Understanding how the relative proportion of DNA deposited by different persons who handled the same object evolves through time has important bearings. For instance, this information may help determine whether the major contributor in a mixed DNA profile is more likely to correspond to the object owner or to the person who may have stolen this object. In this perspective, a simulation-based protocol was designed where randomly paired participants were asked to act either as first (object owner) or second (last) users. The first user was asked to handle/wear 9 different plastic-, metal-, nitrile- and fabric-made objects, commonly found at burglary/robbery crime scenes, for a minimum of 20 min during 8 or 10 consecutive days. The second user subsequently used them for 5, 30 or 120 min in three distinct simulation sessions. The analysis of the relative DNA contribution on the resulting 234 mock DNA traces revealed a large variability in the contribution depending on the time, substrate and pairs of participants. Despite this, a progressive increase of the second user’s DNA contribution, relative to the first user, was observed over time in 93% of the traces. The second user was shown to become the major contributor in approximately 15%, 33% and 55% of the traces recovered from objects used for 5, 30 and 120 min, respectively. Single-source DNA profiles were shown to represent only 1% of the traces. In addition, the DNA profiles of 165 out of 234 (71%) simulated traces displayed extra alleles. Most of these occurred in the minor fraction of mixed DNA profiles and were interpreted as artefacts. Nevertheless, DNA profiles of known participants either involved or not in the simulations were observed in 9 cases (4%). This confirms that indirect DNA transfer should be taken into account when interpreting “touch” DNA evidence.
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- DNA fingerprinting secondary transfer from different skin areas: morphological and genetic studies.Forensic Sci. Int. Genet. 2014; 11: 137-143
- DNA fingerprints from fingerprints.Nature. 1997; 387: 767
- Cell free DNA as a component of forensic evidence recovered from touched surfaces.Forensic Sci. Int. Genet. 2012; 6: 26-30
- Morphological study of fragmented DNA on touched objects.Forensic Sci. Int. Genet. 2008; 3: 32-36
- Fingerprints as evidence for a genetic profile: morphological study on fingerprints and analysis of exogenous and individual factors affecting DNA typing.J. Forensic Sci. 2003; 48: 1-7
- Generation of DNA profiles from fabrics without DNA extraction.Forensic Sci. Int. Genet. 2010; 4: 137-141
- Are you collecting all the available DNA from touched objects?.Int. Congr. Ser. 2003; 1239: 803-807
- Fingerprints from fingerprints.Int. Congr. Ser. 2003; 1239: 953-957
- DNA transfer: review and implications for casework.Forensic Sci. Int. Genet. 2013; 7: 434-443
- Forensic trace DNA: a review.Invest. Genet. 2010; 1: 1-14
- Trace DNA: a review, discussion of theory, and application of the transfer of trace quantities of DNA through skin contact.J. Forensic Sci. 2002; 47: 442-450
- DNA transfer within forensic exhibit packaging: potential for DNA loss and relocation.Forensic Sci. Int. Genet. 2012; 6: 158-166
- Evaluation of multiple transfer of DNA using mock case scenarios.Leg. Med. 2012; 14: 40-46
- Investigation of secondary DNA transfer of skin cells under controlled test conditions.Leg. Med. 2010; 12: 117-120
- Misleading DNA Evidence: Reasons for Miscarriages of Justice.Elsevier, London, England2014
- Secondary and subsequent DNA transfer during criminal investigation.Forensic Sci. Int. Genet. 2015; 17: 155-162
- Following the transfer of DNA: how far can it go?.Forensic Sci. Int. Genet. Suppl. Ser. 2004; 4: 53-54
- The propensity of individuals to deposit DNA and secondary transfer of low level DNA from individuals to inert surfaces.Forensic Sci. Int. 2002; 129: 25-34
- Good shedder or bad shedder-the influence of skin diseases on forensic DNA analysis from epithelial Abrasions.Int. J. Leg. Med. 2012; 126: 179-183
- The tendency of individuals to transfer DNA to handled items.Forensic Sci. Int. 2007; 168: 162-168
- Assessment of individual shedder status and implication for secondary DNA transfer.Forensic Sci. Int. Genet. Suppl. Ser. 2008; 1: 415-417
- Secondary DNA transfer of biological substances under varying test conditions.Forensic Sci. Int. Genet. 2010; 4: 62-67
- The transfer of touch DNA from hands to glass, fabric and wood.Forensic Sci. Int. Genet. 2012; 6: 41-46
- Following the transfer of DNA: how does the presence of background DNA affect the transfer and detection of a target source of DNA?.Forensic Sci. Int. Genet. Suppl. Ser. 2015; 19: 68-75
- The influence of substrate on DNA transfer and extraction efficiency.Forensic Sci. Int. Genet. 2013; 7: 167-175
- The deposition and persistence of indirectly-transferred DNA on regularly-used knives.Forensic Sci. Int. Genet. Suppl. Ser. 2015; 5: 498-500
- The complexities of DNA transfer during a social setting.Leg. Med. 2015; 17: 82-91
- Trace DNA and street robbery: a criminalistic approach to DNA evidence.Forensic Sci. Int. Genet. Suppl. Ser. 2009; 2: 544-546
- Persistence of DNA deposited by the original user on objects after subsequent use by a second person.Forensic Sci. Int. Genet. 2014; 8: 219-225
- Exploring the relative DNA contribution of first and second object’s users on mock touch DNA mixtures.Forensic Sci. Int. Genet. Suppl. Ser. 2015; 5: 300-301
- Trace evidence characteristics of DNA: A preliminary investigation of the persistence of DNA at crime scenes.Forensic Sci. Int. Genet. 2009; 4: 26-33
- Double swab technique for collecting touched evidence.Leg. Med. 2007; 9: 181-184
- Forensic evaluation of the QIAshredder/QIAamp DNA extraction procedure.Forensic Sci. Int. 2006; 156: 70-73
- Postmortem stability of DNA.Forensic Sci. Int. 1988; 39: 59-70
- Advanced Topics in Forensic DNA Typing: Methodology.Elsevier Academic Press, San Diego2012
- An investigation of the rigor of interpretation rules for STRs derived from less than 100 pg of DNA.Forensic Sci. Int. 2000; 112: 17-40
- Consensus and pool profiles to assist in the analysis and interpretation of complex low template DNA mixtures.Int. J. Leg. Med. 2013; 127: 11-23
- Modeling one complete versus triplicate analyses in low template DNA typing.Int. J. Leg. Med. 2014; 128: 259-267
- Low-template DNA: a single DNA analysis or two replicates?.Forensic Sci. Int. 2016; 264: 139-145
- Shedder status—an analysis of self and non-self DNA in multiple handprints deposited by the same individuals over time.Forensic Sci. Int. Genet. 2016; 23: 190-196
- Could secondary DNA transfer falsely place someone at the scene of a crime?.J. Forensic Sci. 2016; 61: 196-203
- Specific and sensitive mRNA biomarkers for the identification of skin in ‘touch DNA’ evidence.Forensic Sci. Int. Genet. 2012; 6: 548-558
- A multiplex (m)RNA-profiling system for the forensic identification of body fluids and contact traces.Forensic Sci. Int. Genet. 2012; 6: 565-577
- Evaluation of mRNA markers for estimating blood deposition time: towards alibi testing from human forensic stains with rhythmic biomarkers.Forensic Sci. Int. Genet. 2015; 21: 119-125
- The nucleic acid revolution continues −will forensic biology become forensic molecular biology?.Front. Genet. 2014; 5: 44
Published online: July 11, 2016
Accepted: July 5, 2016
Received in revised form: June 11, 2016
Received: February 22, 2016
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