And next time you hear about how much crime numbers are improving

in Britain, remember this:
Date disclosed in a parliamentary answer showed that many crimes go unsolved by police, and even when offenders are identified, they are often dealt with by “out of court” penalties like cautions and fines.

In 2008/09, the detection rate for offences against the person – which include assault, wounding and grievous bodily harm – was 47 per cent, the lowest since 2000/01.

Of those offences that were detected and dealt with by the police, 31 per cent resulted in a caution.
That's for violent crimes, remember.
Someone who is cautioned does not have criminal record, although details are stored on a police database.
'does not have a criminal record'; want to bet that also means 'not on the official record of crimes' or 'not numbered in the official record of offenses'?

For sexual offences, the detection rate was 32 per cent, up on the previous year but down from 43 per cent in 2000/01. The caution rate for detected sexual crimes was 17 per cent.

For burglary, the detection rate was 13 per cent, the highest for a decade. But only 50 per cent of detected burglaries led to a criminal charge being brought. Six per cent led to cautions and the rest, 44 per cent, were “taken into consideration” with other offences.

Chris Grayling, the shadow home secretary, said the figures showed ministers are letting criminals “get away with it.”
Not only are criminals getting away with it, I'll bet you this is being used to cook the books(again? more?) to make things look better than they actually are.

Last month, it was revealed that more than half a million serial criminals have been let off with repeated cautions.
Yeah, that's working really well, isn't it?