How can a family member prove that the person who been summoned to be in jury duty doesn't live in the United States anymore for the past 3 years?

U can come to the building go to the jury clerks office and tell them this person nolonger lives here. The jury clerks office is open from 9-4 M-F. If it's a Supreme civil summons its 360 Adams st. If its Supreme Criminal its 320 Jay st. Look at the date on the summons

I believe you just have to call up the king's county court system and let them know that and see what happens from there..Just find the court system for king's county on Google..I'm not sure of the number on the top of my head..Good luck!