A link a friend sent me made me want to remind people that: DNA evidence can be fabricated!
Scientists in Israel have demonstrated that it is possible to fabricate DNA evidence, undermining the credibility of what has been considered the gold standard of proof in criminal cases.
The scientists fabricated blood and saliva samples containing DNA from a person other than the donor of the blood and saliva. They also showed that if they had access to a DNA profile in a database, they could construct a sample of DNA to match that profile without obtaining any tissue from that person.
“You can just engineer a crime scene,” said Dan Frumkin, lead author of the paper, which has been published online by the journal Forensic Science International: Genetics. “Any biology undergraduate could perform this.”
“DNA is a lot easier to plant at a crime scene than fingerprints,” she said. “We’re creating a criminal justice system that is increasingly relying on this technology.”
For those interested, the actual paper which this article is based on: "Authentication of forensic DNA samples", by Dan Frumkin, Adam Wasserstrom, Ariane Davidson, and Arnon Grafit.
(Of course, many people saw DNA evidence fabrication in the realm of possibility before this paper came out. But this paper gives people an example to point to.)
I should note though that one of the author’s of the paper (Dan Frumkin) has founded a company which claims to have developed a test which can detect fabricated DNA evidence using the techniques he describes.
Of course, one might wonder if there are any techniques for fabricating DNA evidence that this (or any other test) cannot detect? There could be a tactical advantage to being able to fabricate DNA evidence, in an undetectable manner, for some people. It’s just speculation on my part, but absence of evidence is not evidence of absence, of course.