Catches case of Columbo with 'one more thing' (4)
I believe the answer is:
cops
'catches' is the definition.
(cop can mean to apprehend)
'case of columbo with one more thing' is the wordplay.
'case of' suggests removing the centre (outsides of).
'with' means one lot of letters go next to another.
'one more thing' becomes 'ps' (as in a postscript in a letter).
'columbo' with its middle taken out is 'co'.
'co'+'ps'='COPS'
(Other definitions for cops that I've seen before include "Familiar American policemen" , "Panda owners" , "The police (sl.)" , "Police (slang)" .)