Judge dismissing half of crimes -- sign of nerves (6)
I believe the answer is:
critic
'judge' is the definition.
(I know that critic is a type of judge)
'half of crimes sign of nerves' is the wordplay.
'half of' suggests halving the letters.
'sign of nerves' becomes 'tic' (as in a nervous tic).
'crimes' halved is 'cri'.
'cri'+'tic'='CRITIC'
'dismissing' is the link.
This may not be right. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for critic that I've seen before include "Arts reviewer" , "Reviewer - fault-finder" , "One judges the merit of artistic works" , "I might rebuke" , "Reviewer of plays, films etc" .)