Your issue is demonstrated to us in Halifax, when police were advising us that it often took too long--90, 180 days--and as a result they weren't even submitting DNA samples.
Those issues for the local data banks and laboratories are something distinct from the DNA data bank itself, but for the use of DNA, all I can say is that I found it extremely worrying and something that should be of general concern because it can help with regard to the investigation, the identification of a wrongdoer, and the exoneration of the innocent.