Scientists in Israel have demonstrated that DNA evidence can be fabricated relatively easily.
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.”
I'm actually happy that DNA evidence is getting more scrutiny. I've long been uneasy with the growing dependency on DNA evidence for criminal convictions... maybe a decline in DNA credibility will lead to a resurgence of a broader range of investigatory techniques.