Sitting as a justice of the peace in 1849 in Monmouthshire, John Rolls was a compulsive sketcher.
He used this talent to add his own illustrations to the formal court calendar of the cases brought before him.
One cartoon (right) shows a mother and daughter dancing a jig after they were cleared of concealing the birth of a child. Others show a mugging (above), forgery, manslaughter and burglary.
Interviewed by Penny Arnold for Look Up Your Genes on BBC Radio Wales, Mr Hopkins said court records were important sources of information for family historians.
But of the hundreds of court calendars held in the archives at County Hall in Cwmbran, he said the document illustrated by Rolls was unique.
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