I think this captures the fact that the body may comprise several members.

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Note added at 16 hrs (2014-01-17 00:51:04 GMT)
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Examples:
From the 4th to the 8th century, the castle was used as municipal tribunal and prison.

She considers the limited accessibility to the Freiburg porch, visible on high feast days and the site of the Freiburg municipal tribunal
http://arthist.net/reviews/21

As has been recently pointed out, in late medieval Italy coats of arms were not used ..... 24, this bull marked the location of a particular municipal tribunal

The king sent the petition to a special municipal tribunal in Warsaw dealing with city matters. The administrator of Sandz was ordered to appear before the tribunal but the verdict is not known.
http://www.jewishgen.org/yizkor/Nowy_sacz/now021.html

And in particular the law of England does in many cases refer itself to it, and ..... property, “no municipal tribunal has authority to enforce such an obligation

Accounts survive from medieval times which detail the trials of knights held .... For a 'municipal tribunal', Leipzig produced a useful precedent for the later.

London had t;hlen likewise a chief municipal tribunal firom the the conquest of England.