Press one criminal to answer (8)
I believe the answer is:
response
'answer' is the definition.
('response' can be a synonym of 'answer')
'press one criminal' is the wordplay.
'criminal' is an anagram indicator.
'press'+'one'='pressone'
'pressone' with letters rearranged gives 'RESPONSE'.
'to' acts as a link.
(Other definitions for response that I've seen before include "Sees porn (anag) - answer" , "Preens so by way of answer" , "comeback" , "Reaction, reply" , "bid by partner" .)