John Rigbey died earlier this month. He was an ex-Flying Squad officer in the 1960s and 1970s, but also a one-man training ground for young advocates (or at least for one).

I first encountered him a few weeks after I qualified. He fitted the Flying Squad mode du jour — natty suit, pork pie hat. Headgear was more or less compulsory for the squad in those days. He was in a hurry. His case had to be on early because he had far better things to do than give evidence in ‘sus’ cases.

My client was challenging Rigbey’s evidence and I asked to see his notebook. He handed it over, saying to look only at pages 7-9 because there were other more important notes throughout the book.

‘When did you make this up?’ I asked. He almost leered at me because one more false step and in went my client’s character. Then he relented: ‘I compiled it in the canteen as soon as possible after the incident.’

He was the sort of officer who could turn things against you in a trice and therefore an invaluable teacher even if the client suffered. ‘My client is of good character?,’ I asked. ‘No, sir.’ ‘But he has no criminal convictions?’ ‘That’s not what you asked sir. He consorts with thieves and prostitutes so he is not of good character.’ Choose your words carefully.

Rigbey was a wonderful raconteur. A favourite tale is of the trial at a magistrates’ court when a barrister challenged his evidence. The chairman came to his rescue, though intervened would be a better word. ‘Sit down, mister’, said the chairman, ‘If I think the copper’s lying, I’ll say so; until then sit down and be quiet.’

After Rigbey retired he wrote a series of crime novels set in the 1970s. The best is probably The Strange Michael Folmer, a clever twist on Jack the Ripper. On the anniversary of the murders, a similar one is committed. When the police receive a letter boasting about the killings they take a fingerprint. But it is that of a man hanged 30 years earlier.

James Morton is a writer and former criminal defence solicitor