The law has one, too, to shoulder
I believe the answer is:
arm
'shoulder' is the definition.
(thesaurus)
'the law has one' is the wordplay.
'the law' becomes 'rm' (I can't explain this - if you can you should give a lot more credence to this answer).
'has' is a charade indicator (letters next to each other).
'one' becomes 'a' (a thing is one thing).
'rm' put after 'a' is 'ARM'.
'too to' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for arm that I've seen before include "Steel" , "Limb or branch" , "Part of chair" , "What soldiers do" , "inlet" .)