From 1 April 2007 the rules governing recording of non-sanction detections were revised to reduce the scope within which they can be claimed to a very small limited set of circumstances. This has significantly reduced the number of non-sanction detections which has been reflected in the overall detection rates.
The Home Office now uses 'sanction detections' as the preferred measure for detections data.
Sanction detections are offences which are cleared up through a formal sanction against an offender i.e. by an offender being charged or summonsed, cautioned, having an offence taken into consideration, receiving a penalty notice for disorder or receiving a warning for cannabis possession.
The sanction detection rate was 20 per cent. in 2004-05. The rate then rose in successive years between 2004-05 and 2007-08 when it was 28 per cent. The sanction detection rate remained at 28 per cent. in 2008-09, a rise of eight percentage points over the 2004-05 figure.