Transported to a prison, killer in trap? (3,6)
I believe the answer is:
rat poison
'killer in trap?' is the definition.
'rat poison' can be an answer for 'killer' (I've seen this before). I am unsure of the 'in trap?' bit.
'transported to a prison' is the wordplay.
'transported' indicates an anagram.
'to'+'a'+'prison'='toaprison'
'toaprison' is an anagram of 'RAT-POISON'.
Can you help me to learn more?
(Other definitions for rat poison that I've seen before include "Rodent killer" , "eliminator of pests" , "Vermin exterminator" , "alternative to piper?" , "Assistance in exterminating" .)