Think carefully about prisoners before dire reforms (8)
I believe the answer is:
consider
'think carefully about' is the definition.
(I've seen this before)
'prisoners before dire reforms' is the wordplay.
'prisoners' becomes 'cons'.
'before' says to put letters next to each other.
'reforms' indicates anagramming the letters.
'dire' is an anagram of 'ider'.
'cons'+'ider'='CONSIDER'
(Other definitions for consider that I've seen before include "Deliberate" , "Hold" , "Deem to be, believe" , "Think about - judge" , "Suppose" .)