Which preposition to use with adjudicator

in Occurrences 2%

Being officially connected with the administration of the apprenticeship system, and tire adjudicators in all difficulties between master and servant, their views of the system and of the conduct of the different parties are entitled to special consideration.

between Occurrences 1%

So far we have said scarcely a word about the prospects of party politics and the problems of government that arise as the State ceases to be a mere impartial adjudicator between private individuals, and takes upon itself more and more of the direction of the general life of the community. VI.

Which preposition to use with  adjudicator