4 Comments

1. 

   Chris Halkides on February 10, 2014 at 5:28 pm

   One would ordinarily expect that the paramedics would change gloves from one case to the next. Assuming that this is true, one wonders how the DNA got transferred.

   • 

     dnadmin on February 11, 2014 at 9:03 am

     Hi Chris,
     Thanks for your comment. This phenomenon goes to the separate ideas of ‘clean’ and ‘DNA clean’, and of course the incredible sensitivity of today’s forensic DNA testing methods. No doubt the paramedics aren’t going from call to call covered in blood from the previous patient. But, they are exposed to all sorts of body fluids in their work, some of which may be invisible. Also, cleaning up may remove the physical stain, but still leave some DNA behind.

     It could be as simple as one patient coughing/drooling on an EMT’s shirt and then the EMT’s shirt comes into contact with the next patient’s fingernails.

     I’m not terribly surprised that this happens. It just goes to how easily DNA can transfer and the difficulty of ‘tracking’ invisible DNA. If you look at the quality control records of most if not all DNA laboratories, you will most likely see instances where analysts have inadvertently transferred their DNA profile onto evidence. If it can happen in a controlled environment like an accredited crime lab, who knows what might be happening out in the field!

2. 

   dnadmin on February 11, 2014 at 9:24 am

   I’ve also heard of the pulse oximeter as a suspected culprit.

3. 

   Christopher John Halkides on February 12, 2014 at 8:43 am

   One reason that I am interested in the Lukis Anderson case is that the Italian Court of Supreme Cassation has set forth the notion that the route of contamination must be proved (this came via the Knox/Sollecito case). In the Jaidyn Leskie and Farah Jama cases the exact route is unclear, as far as I can determine.