Case 1:
A Hampshire Police officer is clocked doing 60% over the speed limit. After a 'thorough' investigation (stop laughing at the back!), Hampshire Police say they cannot find the culprit, who thus gets off scot-free.
Case 2:
A biker is clocked doing 50% over the speed limit, without licence-plates. Bedfordshire Police do a thorough investigation (for once) and secure a prosecution for careless driving and a one-year ban.
One rule for them....