Catch sight of first two escaping with leaders in prison yard (4)
I believe the answer is:
espy
'catch sight of' is the definition.
(to espy is to spot or catch sight of)
'first two escaping with leaders in prison yard' is the wordplay.
I cannot really see how this works, but
'yard' could be 'y' (abbreviation) and 'y' is located in the answer.
The remaining letters 'esp' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for espy that I've seen before include "See" , "Spot, notice" , "Discern" , "Make out at a distance" , "Pick out at a distance" .)