The available information is given in the tables placed in the House Library. Homicide detection rates for individual police forces are only available from 2000-01 onwards.
Non-sanction detections that contribute to the overall detection rate have fallen in recent years reflecting a significant shift by many police forces away from recording detections of crime where no further action is taken. For this reason overall detection rates over time are not fully comparable. 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 limited set of circumstances.