Increase scope of criminal case and others under review (8)
I believe the answer is:
escalate
'increase scope of' is the definition.
(to escalate is to become more intense)
'criminal case and others under review' is the wordplay.
'criminal' is an anagram indicator.
'and others' becomes 'etal' (synonyms).
'under review' shows that the letters should be reversed in order (letters viewed from the other direction).
'etal' written backwards gives 'late'.
'case' is an anagram of 'esca'.
'esca'+'late'='ESCALATE'
(Other definitions for escalate that I've seen before include "Intensify" , "Increase in extent or intensity (8)V" , "Increase in magnitude" , "Increase in intensity or extent, like trouble brewing" , "Raise to higher level, perhaps war" .)