Regarding jury service VW.Org
It's down to the conscience these days.
We had one older brother who did all the research and before the judge gave him the "as a Christian I cannot judge other people etc etc," and was fortunate enough to be left off.
Whereas our congregation secretary made no bones about having served twice on jury service, and in particular a case where as he said, "we nailed the b****rd."
And yes, he has a reputation for a similar attitude in judicial committees I am told.