Does this make sense? The discovery of DNA has helped in the accurate safeguarding of the law system.
I would prefer:
The discovery of DNA has helped in safeguarding the legal system's accuracy.
Putting "accurate" and "safeguarding" together, as in the original version, implies that "accurate" is an adjective describing "safeguarding". If this is to make sense, then it is legitimate to ask what would it mean to be "inaccurately safeguarding" something.
I believe that the more reasonable intent is to say that (knowledge of) DNA "safeguards accuracy".