Friday, May 25, 2012

What DNA can, and cannot, prove

DNA is a very effective way to identify an individual. Properly used it is almost infallible Only a few cells are needed for DNA identification,

The source of a DNA sample can come from any of saliva, blood, skin cells, sweat, hair or semen. What is important from this list is that DNA proves someone was at a location, but subject to such fact as may be shown from the source of the DNA (for example semen shows sexual activity), nothing else. DNA does not provide a timeline - DNA alone does not say when someone was at a location. Specifically, if skin cell DNA is found at a location of someone who already admitted to being in a location the DNA has proven nothing.


Anonymous said...

"almost infallible"? Only if chain of evidence and processing by lab is perfect. One mislabelled sample or sloppy operator and everything's hooped.

James C Morton said...