A friend of mine is a Magistrate at Bedlington Magistrates' Court just North of Newcastle-upon-Tyne.
He works as a maintenance engineer in a local leisure centre.
It seems that one day last week he was accosted by a group of no less than four plain clothed Police officers whilst inspecting a filter in the swimming pool.
Apparently, quite a frightening experience, they asked him several questions including asking for his precise whereabouts between 11:15 and 11:30 one day the previous week.
Luckily for him he was able to state that he was in Bedlington Magistrates' Court.
He was then asked if anybody would remember him being there.
"Yes", he said thoughtfully "Some 40 Magistrates, a District Judge, seven or eight Police officers upto the rank of Superintendent, A couple of dozen solicitors, at least four Court Clerks, two barristers... oh, and roughly 16 assorted convicted criminals".
I'd say that was alibi enough.
Curiously, this is by no means the first time such a thing has happened.