I'd like to sound a further contra note here. Despite the claims to accuracy DNA testing brings, it merely allows one to be wrong with authority. Eventually one of the many Innocence Projects around the world will strike a false positive; they will free a guilty party. Experts couch DNA hits in terms of duplicate matches occurring 1:1 in a world with a certain multiple population of our own, or likelihood ratio. Ditto apparent evidence leading to a DNA mismatch, but caused through contamination or similar circumstance, which has already occurred.
Fallibility cuts both ways. We can error on the side of caution or recklessness, but we will error.
Fallibility cuts both ways. We can error on the side of caution or recklessness, but we will error.