Photographing the execution (8)
I believe the answer is:
shooting
I believe this clue is a double definition.
'photographing' is the first definition.
('shoot' can be a synonym of 'photograph')
'the execution' is the second definition.
(thesaurus)
(Other definitions for shooting that I've seen before include "Making film" , "- Jacket; - star" , "sort of star?" , "on target" , "Firing" .)