Both the Colusa County Courthouse (1861) and adjacent Hall of Records and County Jail (1861) are on the U. S. Parks list of Historic American Buildings. Photos of both here: http://lcweb2.loc.gov/cgi-bin/query/S?pp/hh:@FIELD(SUBJ+@od1(+california++colusa+county++colusa+))
Colusa

These buildings were often multi-purpose. The bell could have been used for general alarm, fire, announcements, etc. I have seen a bell cupola on some old courthouses in the South, but whether any were used to toll a court decision, I don't know.