When I was young, Scotland Yard had a Black Book. The ACC’s (assistant commissioner, crime) Consolidated Instructions contained a list of naughty lawyers who could be blamed for the failure of a prosecution. It was never that there was not enough evidence.

If it was not an incompetent prosecutor, a senile judge or borderline-IQ jurors, it was a result of perjuring defence witnesses or alibis faked by solicitors.

Not that the prosecution don’t call perjuring witnesses. Think how many confessions are made to cellmates whom the defendants have met a couple of hours earlier. Of course, no question of the witness hoping for dropped charges, probation or anything like that. Pure altruism.

In 1979, when the actor John Bindon was accused of murder, a cellmate, himself on trial for murder, came forward to say he disapproved of murder and that was his motive in giving evidence. Bindon was acquitted; the cellmate convicted.

It happens time and time again, worldwide. In 2014 in Chicago, two lawyers, Beau Brindley and Michael Thompson, were charged with coaching their clients in what the prosecution alleged were lies. The prosecution relied on evidence of changing stories given by the clients under oath, supported by evidence from the convicted criminals themselves, who said it was the work of their briefs.

In August last year, in a bench trial, District Judge Harry Leinenweber acquitted both men, ruling that the prosecution had failed to prove the lawyers knew their clients were lying when they put them in the witness box. The judge noted that each of the former clients who had testified against the pair had already ‘lied at least once under oath’, and some had been offered huge discounts on their sentences to say their lawyers put them up to it.

It has always been a huge risk pointing out defects in a client’s case. ‘There’s CCTV of you in the bank.’ ‘It’s my cousin. He looks just like me.’ ‘You made a confession.’ ‘It was knocked out of me.’ ‘The money was found behind your fireplace.’ ‘That must have been there when I got the house.’ If the story keeps changing it is often better to send the client to other solicitors, but by then he will have perfected his lies.

I cannot recall a prosecution for coaching in Britain in recent times. In fact, it could not happen here now. Could it?

James Morton is a writer and former criminal defence solicitor