A top mobster kidnaps even members of public in Pacific resort (8)
I believe the answer is:
Here is my best explanation:
'pacific resort' is the definition.
(I've seen this before)
'a top mobster kidnaps even members of public' is the wordplay.
'top mobster' becomes 'capo' (senior mafia member).
'kidnaps' is an insertion indicator (I've seen this in other clues).
'even members of' indicates alternate letters (letters in even-numbered positions are used).
The alternate letters of 'public' are 'ulc'.
'capo' placed around 'ulc' is 'capulco'.
'in' acts as a link.
(Other definitions for acapulco that I've seen before include "Mexican holiday destination", "Fashionable resort city in southern Mexico", "foreign resort", "Port", "Mexican Pacific seaside resort", "Mexico port, resort", "Mexican city", "Mexican location", "Fashionable port city of southern Mexico" and "exotic holiday resort".)