Reproduced - police officer, that is - initial document (6)
I believe the answer is:
copied
'reproduced' is the definition.
(copying is a kind of reproducing)
'police officer that is initial document' is the wordplay.
'police officer' becomes 'cop' (cop is a kind of police officer).
'that is' becomes 'ie' (abbreviation for id est, 'that is' in Latin).
'initial' suggests taking the first letters.
The first letter of 'document' is 'd'.
'cop'+'ie'+'d'='COPIED'
(Other definitions for copied that I've seen before include "Imitated, reproduced" , "Imitated or recreated" , "Imitated or replicated" , "Reproduced (something)" , "made a transcript" .)