Line in US pursued by some police hero (2,3)
I believe the answer is:
el cid
'hero' is the definition.
(I've seen this before)
'line in us pursued by some police' is the wordplay.
'line in us' becomes 'el' (short for elevated railway line in the US).
'pursued by' is a charade indicator (letters next to each other).
'some police' becomes 'cid'.
'el'+'cid'='EL CID'
(Other definitions for el cid that I've seen before include "11th century Spanish hero" , "C11 Spanish warrior hero" , "epic movie" , "Eleventh Century Spanish hero" , "Historic fighter" .)