Lie Detectors.

In many American states, polygraphs are common. When a serious crime has been committed - polygraph testing may be offered in order to sift quickly the liars from the truth tellers. I do not advocate its use in courts in the UK without significant amounts of research - but I cannot see a problem in police trying to avoid the huge amounts of time wasting which occurs currently. The one thing that I would say regarding courts, is that JPs and juries would be permitted to draw inferences from any refusal to take the test.
Think how many lengthy trials would be avoided; how much public money would be saved; how many criminals would think twice before making perverse not guilty pleas.