I got called, and I went. We were told the first week was mandatory, the second week was optional. Since I had Administrative Leave and was getting paid, I stayed for both weeks. I was able to sit on a civil case, but no criminal cases. I had previously worked for the Police Department and was currently supporting the CAD system; "Yes, I know the arresting officer and three of the other five patrol officers on the list, I know the detective as well;" defense attorneys challenge that stuff (whether I'd be impartial or not.) Now, you call in the night before to see if you have to report - though I've gotten on "panels" a number of times, I've only had to report the one time. Same with my lovely wife - she got a civil (disability) case, but no criminal cases (she also worked for the PD - it's how we met.)