His third conviction, and his resulting imprisonment, endured for years, but in 1994 Mr Rideau appealed on the ground that blacks had been excluded from the grand jury that brought the indictment against him.

ECONOMIST: Louisiana faces up to the old question

It was his second conviction in six days, his third in seven months (these two for bribery and fraud respectively).

ECONOMIST: The Berlusconi problem

Gilfoyle has had two appeals against his conviction rejected but has lodged a third bid with the Criminal Cases Review Commission (CCRC).

BBC: Convicted killer Eddie Gilfoyle's gagging order lifted

Since roughly a third of sexual crimes are committed by people without a previous conviction, it is inevitable that some people with apparently excellent credentials but sinister intentions are going to get jobs working with children or vulnerable adults.

BBC: NEWS | UK | Can background checks ever work?