Activity level reporting
John Buckleton
The posts on this page are my own and do not reflect those of any organisation I am associated with
Dear friends, we are considering a list of statements that might be useful in court if the situation becamae appropriate. We would welcome informed constructive feedback.
John Buckleton, Duncan Taylor, James Curran and Tim Kalafut
1. Recovery of DNA varies between labs (Gill, Fonnel?p et al. 2024). It may be necessary to use relative amounts.
2. An absence of biological material where that material was expected under Hp almost always supports Ha.
3. Every transfer step is expected to reduce the amount of DNA from the original source remaining. The variance about this expectation is sufficiently high, however, that the highest observations from secondary transfer may be above the lowest from primary transfer.(Carson, Volgin et al. 2022)
4. Carson gives about a 10-30% chance of finding a profile after tertiary transfer. (Carson, Volgin et al. 2022)
5. Persistence of DNA on an immobile object (say carpet) in good conditions may be at least months. (Reither, Gray et al. 2021, Kaesler, Kirkbride et al. 2023, Arsenault, Kuffel et al. 2025)
6. The maximum persistence of DNA under fingernails we have found was 36 hours. (Flanagan and McAlister 2011, Johannessen, Gill et al. 2022);
7. Publications of foreign DNA from under the fingernails from the general population give ranging values. Plausibly about 27% of the general population have foreign DNA under their fingernails.(Cook and Dixon 2007, Dowlman, Martin et al. 2010, Matte, Williams et al. 2012)
8. In a study involving deliberate scratching of another individual (n = 30), 33% of individuals had a foreign DNA profile beneath their fingernails from which the person they scratched could not be excluded as the source; however when sampling occurred 6 h after the scratching event, only 7% retained the foreign DNA.(Matte, Williams et al. 2012)
9. DNA transfer to hand (handshake) and then to surface has been detected up to 5hrs after handshake. (Goray, Eken et al. 2010, Goray, Mitchell et al. 2010, Szkuta, Ballantyne et al. 2018)
10. Habitual user’s DNA was detected on most items as the major donor, regardless of whether it was subsequently handled by another person for a short period of time. The one-time, short duration, user’s DNA was detected on approximately two thirds of the items, albeit typically at quantities lower than the habitual user (Atkinson, Arsenault et al. 2022) The percentage contribution of the 1st user relative to the 2nd user of an object declines in a linear manner, over time.(van Oorschot, Glavich et al. 2014, Oldoni, Castella et al. 2016, Poetsch, Pfeifer et al. 2018)
11. Foreign DNA on the inside of underwear is more probable given intimate contact as compared with non-intimate contact. This is also true for waist bands of touched underwear but the ratio is lower. (Breathnach, Williams et al. 2016)
12. Shedder status may need to be taken into account if there is an indication or suggestion in a case that a person-of-interest deviates from the average population in their shedding ability.
13. The force and friction of contact may impact on the amount of DNA transferred (Goray, Eken et al. 2010, Goray, Mitchell et al. 2010, Tobias, Jacques et al. 2017, Hefetz, Einot et al. 2019). Repeated contacts or uses of an item may result in more DNA being recovered.
14. Any contact with or exposure to the trace- bearing surface may again remove or redistribute latent DNA traces or body fluid stains. Up to half of a stain may be lost from items to their packaging (Goray, van Oorschot et al. 2012, Stella, Meakin et al. 2022, Mercer, Taylor et al. 2023, Taylor, Volgin et al. 2024).
Arsenault, H., A. Kuffel, P. Dugard, N. Nic Daeid and A. Gray (2025). "Trace DNA and its persistence on various surfaces: A long term study investigating the influence of surface type and environmental conditions – Part two, non-metals." Forensic Science International: Genetics 74.
Atkinson, K., H. Arsenault, C. Taylor, L. Volgin and J. Millman (2022). "Transfer and persistence of DNA on items routinely encountered in forensic casework following habitual and short-duration one-time use." Forensic Science International: Genetics 60: 102737.
Breathnach, M., L. Williams, L. McKenna and E. Moore (2016). "Probability of detection of DNA deposited by habitual wearer and/or the second individual who touched the garment." Forensic Science International: Genetics 20: 53-60.
Carson, S., L. Volgin, D. Abarno and D. Taylor (2022). "The potential for investigator-mediated contamination to occur during routine search activities." Forensic Science, Medicine and Pathology 18(3): 299-310.
Cook, O. and L. Dixon (2007). "The prevalence of mixed DNA profiles in fingernail samples taken from individuals in the general population." Forensic Sci Int Genet 1(1): 62-68.
领英推荐
Dowlman, E. A., N. C. Martin, M. J. Foy, T. Lochner and T. Neocleous (2010). "The prevalence of mixed DNA profiles on fingernail swabs." Science & Justice 50(2): 64-71.
Flanagan, N. and C. McAlister (2011). "The transfer and persistence of DNA under the fingernails following digital penetration of the vagina." Forensic Science International: Genetics 5(5): 479-483.
Gill, P., A. E. Fonnel?p, T. Hicks, S. Xenophontos, M. Cariolou, R. van Oorschot, I. Buckel, V. Sukser, S. Papi?, S. Merka?, A. Kostic, A. M. Pereira, C. Teutsch, C. Forsberg, C. Haas, E. Petkovski, F. Hass, J. Masek, J. Stosic, Y. S. Lee, C. K.-C. Syn, L. Groombridge, M. Trimborn, M. Hadjivassiliou, M. Breathnach, J. Novackova, W. Parson, P. Hatzer-Grubwieser, S. Pietik?inen, S. Joas, S. Willuweit, S. Grethe, T. Mili?evi?, T. Hasselqvist, V. Kallupurackal, V. Stenzl, S. Jansson, I. Glocker, S. Brunck, K. Nyhagen, A. B. Dyve Lingelem, H. Autere, D. Thornbury, N. Pedersen, S. Fox, D. Moore, G. Escott, C. B. Petersen, H. J. Larsen, R. Giles, P. S. Allen and I. Bastisch (2024). "The ReAct project: Analysis of data from 23 different laboratories to characterise DNA recovery given two sets of activity level propositions." bioRxiv: 2024.2010.2010.617148.
Goray, M., E. Eken, R. J. Mitchell and R. A. H. van Oorschot (2010). "Secondary DNA transfer of biological substances under varying test conditions." Forensic Science International: Genetics 4(2): 62-67.
Goray, M., R. J. Mitchell and R. A. H. v. Oorschot (2010). "Investigation of secondary DNA transfer of skin cells under controlled test conditions." Legal Medicine 12(3): 117-120.
Goray, M., R. A. H. van Oorschot and J. R. Mitchell (2012). "DNA transfer within forensic exhibit packaging: Potential for DNA loss and relocation." Forensic Science International: Genetics 6(2): 158-166.
Hefetz, I., N. Einot, M. Faerman, M. Horowitz and J. Almog (2019). "Touch DNA: The effect of the deposition pressure on the quality of latent fingermarks and STR profiles." Forensic Science International: Genetics 38: 105-112.
Johannessen, H., P. Gill, G. Shanthan and A. E. Fonnel?p (2022). "Transfer, persistence and recovery of DNA and mRNA vaginal mucosa markers after intimate and social contact with Bayesian network analysis for activity level reporting." Forensic Science International: Genetics 60.
Kaesler, T., K. P. Kirkbride and A. Linacre (2023). "Persistence of touch DNA on commonly encountered substrates in different storage conditions." Forensic Science International 348: 111728.
Matte, M., L. Williams, R. Frappier and J. Newman (2012). "Prevalence and persistence of foreign DNA beneath fingernails." Forensic Science International: Genetics 6(2): 236-243.
Mercer, C., D. Taylor, J. Henry and A. Linacre (2023). "DNA accumulation and transfer within an operational forensic exhibit storeroom." Forensic Science International: Genetics 62: 102799.
Oldoni, F., V. Castella and D. Hall (2016). "Shedding light on the relative DNA contribution of two persons handling the same object." Forensic Science International: Genetics 24: 148-157.
Poetsch, M., M. Pfeifer, H. Konrad, T. Bajanowski and J. Helmus (2018). "Impact of several wearers on the persistence of DNA on clothes—a study with experimental scenarios." International Journal of Legal Medicine 132(1): 117-123.
Reither, J. B., E. Gray, A. Durdle, X. A. Conlan, R. A. H. van Oorschot and B. Szkuta (2021). "Investigation into the prevalence of background DNA on flooring within houses and its transfer to a contacting surface." Forensic Science International 318: 110563.
Stella, C. J., G. E. Meakin and R. A. H. van Oorschot (2022). "DNA transfer in packaging: Attention required." Forensic Science International: Genetics Supplement Series 8: 303-305.
Szkuta, B., K. N. Ballantyne, B. Kokshoorn and R. A. H. van Oorschot (2018). "Transfer and persistence of non-self DNA on hands over time: Using empirical data to evaluate DNA evidence given activity level propositions." Forensic Science International: Genetics 33: 84-97.
Taylor, D., L. Volgin and B. Kokshoorn (2024). "Accounting for site-to-site DNA transfer on a packaged exhibit in an evaluation given activity level propositions." Forensic Science International: Genetics 73: 103122.
Tobias, S. H. A., G. S. Jacques, R. M. Morgan and G. E. Meakin (2017). "The effect of pressure on DNA deposition by touch." Forensic Science International: Genetics Supplement Series 6: e12-e14.
van Oorschot, R. A. H., G. Glavich and R. J. Mitchell (2014). "Persistence of DNA deposited by the original user on objects after subsequent use by a second person." Forensic Science International: Genetics 8(1): 219-225.
Law Student
2 个月It seems pretty simple to me because this is about expert evidence in a court of law. A line must be clear between science and the legal concept. A prosecution expert can cite valid data which makes something appear more likely. A defence expert can then cite valid data which makes that same thing appear less likely. Neither should do that because it's speculation, which does not belong before the courts. The expert should conduct a recognised evaluation.
The posts on this page are my own and do not reflect those of any organisation I am associated with
2 个月I'd like to thank Carol Rogers who entered into the spirit of giving me informed feedback. Unfortunately I have learnt that, CR apart, I cannot use Linkedin to obtain informed public comment.
For those lawyers looking to challenge these opinions, we have a website and are available internationally.
Associate Professor of Forensic Science | Forensic DNA Analyst/Consultant
2 个月This is an interesting collection of studies; however, the sample sizes in many of them are too small to have any statistical power in terms of their findings. I think there is a long way to go before conclusions can be drawn from this collection.
Post Conviction Forensic Consultancy
2 个月Proposed: All relevant people should be tested before LR ratios are generated. This is really important among related family members and people living together. It is malpractice to do otherwise. (Stole this by badly paraphrasing Tim K..sorry).