Well, as I understand it, amongst the Police, the 'Criminal Prosecution Service' (CPS) was, at one point, known as "Can't Prosecute, Sorry!".
As for the Director of of Public Prosecutions, well, I think he deserves a reward - So I think we should club together and buy him a brand new Whitewash brush, he must have worn out the last one on this job.

Cynical? Me?
(Anyone would think I distrusted politicians or something).