One taking stock of leader crossing street (7)
I believe the answer is:
rustler
'one taking stock' is the definition.
(someone stealing farm animals ie stock)
'leader crossing street' is the wordplay.
'leader' becomes 'ruler' (I've seen this before).
'crossing' indicates putting letters inside.
'street' becomes 'st' (abbreviation).
'ruler' placed around 'st' is 'RUSTLER'.
'of' is the link.
(Other definitions for rustler that I've seen before include "one whose stock-taking is dishonest" , "Livestock thief" , "Cattle-thief" , "person taking stock" , "Cattle thief" .)