Now that North Yorkshire Police have still not found what happened to Claudia Lawrence after 12 years-plus, it is in my view time to go to back to the arrangements in the 1950/60s when county police forces called in Scotland Yard to investigate murder.

I had the extraordinary honour and privilege to be a Metropolitan Police cadet at Tooting in 1960/61 when the Head of CID for W Division was DCS John du Rose.

He was one of the most celebrated detectives in the Metropolitan Police at the time and was known as ‘four day Johnnie’.

When called out by local police forces, he was known to solve murders in four days.

In 1962 I was a police officer at Chelsea under DI Bob Huntley, later Commander Bob Huntley, head of the murder squad at Scotland Yard.

I have just re-watched the ITV production of Manhunt where DCI Colin Sutton solved the murder of a girl on Twickenham Green.

Again, in my view, if North Yorkshire police had swallowed their pride and called in DCI Sutton or a detective of similar skills and abilities, we might well have a solved murder.

David Cooper, Topcliffe Parks, Topcliffe