CRB Checks

In these trust-nobody days Criminal Records Bureau checks are routinely required - sometimes when they are an obvious precaution, such as with teachers and youth workers, but also, much of the time as an arse-covering exercise. I play a very small part in a small charity that provides help to young adults with learning difficulties. I do not deal with clients face to face, but I nevertheless had a CRB check (the fact that I have been a JP for two decades does not apparently count). I now do the interviews and form filling for the charity's CRB checks (even for a half-day-a-week volunteer who is the mother of one of our clients). We have so far paid between £1500 and £2000 out of slender resources for these checks and all that we have come up with is a drink-drive on a craft instructor, and a 10 year-old shoplifting on a catering trainer.
It is only recently that magistrates who present Magistrates in the Community roadshows in schools have been told that they no longer need individual CRB checks, since the Lord Chancellor checks us routinely and these roadshows only ever take place with two or more presenters.
Nobody wants to see another Ian Huntley (although the cock-ups in his case meant that checks were done, but the database was inadequate) but is all of this a good use of scarce resources?