Succeeded with murder in facility (5)
I believe the answer is:
skill
'facility' is the definition.
(I've seen this in another clue)
'succeeded with murder' is the wordplay.
'succeeded' becomes 's' (genealogical abbreviation).
'with' is a charade indicator (letters next to each other).
'murder' becomes 'kill' (I've seen this before).
's'+'kill'='SKILL'
'in' is the link.
(Other definitions for skill that I've seen before include "Ability acquired by training" , "Talent" , "Knack" , "facility" , "Expertise, dexterity" .)