According to a new study out of Israel, published in Forensic Science International: Genetics DNA last month, DNA evidence can be fabricated by anyone with access to relatively common scientific instruments.  Scientists were able to take blood taken from a woman, remove all white blood cells (which contain the DNA),   and  add amplified DNA to the remaining red blood cells and plasma.  This essentially replaced the woman’s DNA from the blood with the man’s.   This means that someone could take their own blood, remove the white blood cells, and add in a target peson’s DNA, which could have been pulled from a cigarette butt or drinking cup.

Another technique used by the authors was constructing DNA snippets, short strings of specific DNA,  by cloning  common  DNA snippet variations which could be used to compile a specific genetic profile.  This would not be as labor intensive as it sounds. In forensic DNA testing 13 loci, or areas, are looked at only.  Only 13 different short profiles would have to be made in order to mix together an entire fake DNA profile.  Once somebody established a library of snippets any known profile could be imitated, which means anyone with access to law enforcement databases could find a profile to mimic.

The good news is that there are ways to tell “fake” DNA from unadulterated profiles, as long as an adulteration is being looked for; general DNA analysis will not catch a fake.  Although according to one of the authors “any biology undergraduate could perform [these changes]” and engineer a crime scene, others in the field agree that the average criminal could not fabricate DNA.  Though that may be true, the problem is the fact that it can be done at all and that reasonable doubt can certainly be raised about all DNA evidence if it is not specifically tested for alterations and manipulations.   Once reasonable doubt is raised as to the authenticity of presented DNA evidence law enforcement loses a key forensic tool.

for more on this topic  see this article

Tags: DNA, Evidence, Forensic Science, Law Enforcement

This entry was posted on Friday, September 18th, 2009 at 11:48 am and is filed under Forensics in The News, Fun Facts. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.