A surprise escape from cops (4,4,3,4)
I believe the answer is:
bolt from the blue
'a surprise' is the definition.
(I've seen this in another clue)
'escape from cops' is the wordplay.
I cannot really see how this works, but
'escape' could be 'bolt' (I've seen this before) and 'bolt' is found within the answer.
'from' could be 'o' (I've seen this in other clues) and 'o' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for bolt from the blue that I've seen before include "unexpected event" , "Sprint by university athlete" .)