Doctor raised origin of murder weapon (7)
I believe the answer is:
sidearm
'weapon' is the definition.
(I've seen this before)
'doctor raised origin of murder' is the wordplay.
'doctor' indicates an anagram.
'origin of' indicates taking the first letters.
The first letter of 'murder' is 'm'.
'raised' anagrammed gives 'sidear'.
'sidear'+'m'='SIDEARM'
(Other definitions for sidearm that I've seen before include "One may be fired" , "weapon" , "Piece" , "Officer may carry this" .)