Fugitive's key -- copy key! (7)
I believe the answer is:
escapee
'fugitive's' is the definition.
(escapee is a kind of fugitive)
'key copy key' is the wordplay.
'key' becomes 'esc' ('Escape' key on a computer keyboard).
'copy' becomes 'ape' ('ape' can be a synonym of 'copy').
'key' becomes 'e' (I've seen this in other clues**).
'esc'+'ape'+'e'='ESCAPEE'
(Other definitions for escapee that I've seen before include "prisoner on the loose" , "One flying from" , "One that's broken free" , "Jail-breaker" , "One flees captivity" .)