Psychotic cops lost criminal, causing irritation (5)
I believe the answer is:
itchy
'causing irritation' is the definition.
(I've seen this before)
'psychotic cops lost criminal' is the wordplay.
'lost' suggests deleting specific letters.
'criminal' is an anagram indicator.
'psychotic' with 'cops' removed is 'yhtic'.
'yhtic' anagrammed gives 'ITCHY'.
(Other definitions for itchy that I've seen before include "Wanting a scratch?" , "Feeling as if one wants to scratch" , "Unable to relax" , "Needing a scratch" , "Fidgety" .)