SIR – Your recent ‘shock horror’ story about the low conviction rate for street robberies needs to be put into its proper context. (T&A, August 21).

Readers with very long memories might recall the downfall of Sergeant ‘Tanky’ Challoner some 40-odd years ago.

He was the Metropolitan Police’s champion thief-taker but his career came to an abrupt end after he arrested two offenders in separate incidents and charged them with carrying an offensive weapon.

When the cases came to trial it was found that the so called weapons were two halves of the same brick.

The subsequent uproar began the long process of replacing a system of crime and punishment where by the villains knew what to expect with one based on the rule of law.

Many people think that this has led to too many offenders getting away with it as these days prosecutions will only proceed if an independent adjudicator – the Director of Public Prosecutions – considers there is sufficient evidence to convince a court.

In the circumstances I think it is remarkable that up to 40 per cent of street robberies, where independent witnesses are a rarity, are detected and successfully prosecuted.

Brian Holmans, Langley Road, Bingley