A sudden rise in the rate of law-breaking (5,4)
I believe the answer is:
crime wave
'a sudden rise in the rate of law-breaking' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for crime wave that I've seen before include "rise in vice" , "multitude of sins" , "Sudden rise in offences" , "Sudden rise in the rate of law-breaking" , "Busy time for law" .)