Talk:Touch DNA

Controversy
How is there no section questioning the use of “touch DNA”? There are many, many cases of innocent people being sent to prison by this evidence, and many are starting to question whether it’s reliable at all.

https://www.nationalreview.com/2017/01/touch-dna-evidence-can-lead-convictions-innocent-people/ SheldonHelms (talk) 21:38, 28 June 2019 (UTC)


 * I don't think we should create a section about questioning reliability of touch DNA. It is not unreliable science. It's either a this person's DNA or another person's DNA. How lawyers use it in court is a different matter. Plunged (talk) 11:46, 8 August 2019 (UTC)

The expression "touch DNA" is misleading, since it implies or suggests direct transfer from a person to a surface when she touches it. Dozens or even hundreds of studies have already demonstrated that a person's DNA may be deposited in a surface via indirect transfer (secondary, tertiary and so on), which means that no "touch" is required for DNA transfer. Indeed, no touch is required even whe we consider direct transfer (think of someone sneezing near to a surface). The use of the expression "touch DNA" is thus misleading because it implies / suggests that a suspect touched an object or a victim, i.e., it suggests activity (usually a crime) and hides other possible mechanisms of DNA transfer. The Lukis Anderson case is a clear example of how misleading such an expression may be. For research on indirect DNA transfer, see any study by Van Oorschot, for instance. — Preceding unsigned comment added by 186.212.193.83 (talk) 20:36, 7 March 2021 (UTC)

Regarding the use of the expression "touch DNA", see footnote 4 of this paper: 10.1016/j.fsigen.2019.102186

"Footnote 4: The term ‘trace DNA’ is preferred to ‘touch’ or ‘contact’ DNA since the latter terms imply a mode of transfer that may be misleading: we cannot know if the activity of touching has actually occurred; the term 'contact' is vague. Activity-level considerations must be provided in properly formulated propositions; the term 'trace-DNA' is used to refer to the presence of low quantity DNA, and nothing more." — Preceding unsigned comment added by 186.212.193.83 (talk) 20:42, 7 March 2021 (UTC)