While I agree with Amos, there is also the problem that 'factual' evidence is becoming increasingly difficult to understand for tne non-specialist. I am thinking about DNA testing in particular, where the 'professional liar' can easily mislead the nonspecialised jurors who may not understand how things like correlated traits and the effects of localized groups can lead to differences of many millions in the likelihood the DNA is or is not from the accused, victim or bystander. What the solution to this is, I don't know, but I am certain it is not to trust the professionals more!