Coroner out of order -- deed, at last, documented (2,6)
I believe the answer is:
on record
'documented' is the definition.
(thesaurus)
'coroner out of order deed at last' is the wordplay.
'out of order' is an anagram indicator.
'at last' suggests the final letters.
The last letter of 'deed' is 'd'.
'coroner' is an anagram of 'onrecor'.
'onrecor'+'d'='ON RECORD'
(Other definitions for on record that I've seen before include "Officially noted" , "officially acknowledged" , "Publicly known - stated in published document" , "Officially recognised" , "where needles used to be put" .)