DNA - Do Not Assume
It is being reported that new studies show that contamination of evidence is an issue which should be given more consideration than has been suggested. The research show that caution needs to be exercised when intrepreting so-called "touch" DNA, particularly as it becomes nore widley relied on.
In the opinion of Beriocn this typifies the belief of many forces that DNA evidence is the most cost-effective means of solving a crime.
Caution is the name of the game - as it always should be with any scientific development.