Stupid person picks pocket, getting credit (8)
I believe the answer is:
dipstick
'stupid person' is the definition.
(I know that stupid person can be written as dipstick)
'picks pocket getting credit' is the wordplay.
'picks pocket' becomes 'dips' (dip can mean to pick someone's pocket).
'getting' says to put letters next to each other.
'credit' becomes 'tick' (I've seen this before).
'dips'+'tick'='DIPSTICK'
(Other definitions for dipstick that I've seen before include "Fool" , "shower of liquid" , "Engine oil measurer" , "Rod used to measure oil level in car" , "Graduated rod for measuring oil levels" .)