One arrested by the force? (5)
I believe the answer is:
thief
'one arrested by the force?' is the definition.
I can't judge whether this defines the answer.
'one arrested by the force?' is the wordplay.
'one' becomes 'I' (Roman numeral).
'arrested by' is an insertion indicator (I've seen this in other clues).
'force?' becomes 'F' (symbol used in Physics e.g. f=ma).
'i' placed into 'the' is 'thie'.
'thie'+'f'='THIEF'
(Other definitions for thief that I've seen before include "One with taking ways" , "See 3" , "Pilferer" , "nicker?" , "Person who steals things" .)