Television: Holmes and the consultants mystery
Timeshift: How To be Sherlock Holmes (BBC Four) Gairdini na Lus (TG4) Nationwide (RTE1) In Good Hands (RTE1)
Sherlock Holmes was, if you'll pardon the expression, a consultant.
Or a consulting detective, as they described him in Timeshift: How To Be Sherlock Holmes, which traced the evolution of the character on screen from the silent movies all the way up to the BBC's Sherlock of today.
So he has assumed many forms, but always, he has been a consultant. I suppose we don't think about him in those terms, because our main instinct is just to call him a detective -- yet he is not officially employed by anyone on a full-time basis in the public or the private sector, instead he is someone who is, well, consulted.