Parent recalls famous murderer being a highly deranged person (6)
I believe the answer is:
maniac
'deranged person' is the definition.
(I've seen this before)
'parent recalls famous murderer' is the wordplay.
'parent' becomes 'ma' (ma can mean mum or mother).
'recalls' is a reversal indicator (I've seen 'recall' mean this).
'famous murderer' becomes 'cain' (Cain who killed Abel. I am not sure about the 'famous' bit.).
'cain' in reverse letter order is 'niac'.
'ma'+'niac'='MANIAC'
'being a highly' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for maniac that I've seen before include "Psycho" , "Crazy person behaving wildly" , "One behaves wildly or with excessive enthusiasm" , "Mad (keen) type" , "Psychopath" .)