Crime involving firing (5)
I believe the answer is:
arson
This clue is a double definition.
'crime' is the first definition.
(crime of illegally starting a fire)
'firing' is the second definition.
(starting fires)
'involving' is the link.
(Other definitions for arson that I've seen before include "Fire-lighting crime" , "Incendiary crime" , "Illegally firing" , "Crime of fire-setting (5)" , "Pyromaniac's crime" .)