Cruel treatment in LA bus examined (5)
I believe the answer is:
abuse
'cruel treatment' is the definition.
(I've seen this before)
'in la bus examined' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ABUSE' is hidden in the letters of 'la bus examined'.
(Other definitions for abuse that I've seen before include "Berate - exploitation" , "Misemploy - invective" , "Utter insults, attack in words" , "vilification" , "Party official; dessert" .)